RFID tags are usually small, but they can be much larger depending on the power source and the consumer’s needs. Jun 14, 2022 · The working of RFID label is different from the barcode and UPC codes as it doesn’t require a line of sight to transmit radio waves between the scanner device and label. It does this by broadcasting a radio signal that is picked up by a receiver. Powering the Card: The electromagnetic field generated by the reader’s antenna powers the RFID card. Jun 6, 2023 · Definition of RFID technology. These devices are the only way to print on labels, and they also save time by automating the manual process of encoding each tag. High Frequency (HF) – 13. 6 Mar 2023. This article Jul 9, 2024 · Cool Opportunities: With an RFID card, you can do some neat things. All US passports issued after 2006 have RFID chips that track your photo and information. This is used to allow transactions without the need to type anything into any device. These tags come in various forms, such as stickers, cards, or even embedded in products. Metro cards have RFID chips for quick swiping, and dogs are implanted with RFID chips for tracking. The process involves several key components and steps: 1. What I'm using it to test out here are Vulkit RFID blocking cards, which are designed to protect credit cards, debit cards, and ID cards using 13. The speed and ease of RFID scanning enables employees to check inventory levels more frequently, which supports more accurate inventory counts, order forecasts and order amounts, resulting in decreased storage costs and overall costs. How does RFID work? Using RFID tags to tag items allows users to automatically and uniquely identify and track inventory and assets. Use an RFID reader to scan the tag and read back the information you have They're good for the life span of the pet. Oct 17, 2023 · 1. RFID systems consist of RFID tags (which contain a microchip and antenna), RFID readers (that emit radio waves to activate the tags) and a backend system (that manages and processes the data collected by the Sep 24, 2022 · RFID stands for radio-frequency identification. RFID sensor. RFID (radio-frequency identification) is a method of wireless communication that uses electromagnetic waves to identify and track tags attached to objects. The RFID transponder is comprised of a microchip that holds information to identify an object, product, or person and an antenna for transmitting this data to the reader. RFID tags are used in a variety of applications, such as tracking inventory or assets, monitoring livestock, and identifying people or animals. So how to tell if a wallet is May 8, 2022 · If you are a high-value target, such as an employee with an access card to valuable or sensitive assets, then using an RFID-blocking sleeve or wallet is sensible. But the information credit cards transmit by RFID is also very limited. Employees IDs. An RFID wallet is only as effective as the quality of its design. So, in this video, what is RFID, what is inside this RFID system, how RFID Apr 29, 2024 · An RFID tag is an electromagnetic chip that both sends and receives information. RFID systems include a radio transponder, receiver, and transmitter. It uses radio frequency to search, identify, track, and communicate with items and people. There is no perfect tag for all applications. A tag is attached to the object that needs to be identified/tracked. RFID Tags: RFID tags are small electronic devices that contain an antenna and a microchip. An NFC RFID tag, similar to a QR code, can easily push users to a digital landing page so that they can learn more information about a brand, product, or campaign. Inventory tracking. We'll explain how RFID works, the different types of RFID Feb 25, 2024 · An RFID access control system works by using RFID technology to authenticate and authorize individuals' entry into secure areas. Continue reading to Oct 17, 2023 · How Does RFID Technology Work? RFID technology, or radio frequency identification technology, uses electromagnetic fields to automatically identify and track tags attached to objects. Transponders are similar to the passive RFID tags wherein using the reader is required to transmit data. The access control software compares the card's Adam Volle. RFID technology, which stands for R adio F requency Id entification technology, is a system consisting of an RFID transponder (a combination of transmitter and responder), antenna, and an RFID reader, also called interrogator and interpreter. The control device sends a signal to the chip in the form of radio waves. The two ends of the system communicate using electromagnetic fields. The data is then verified by the printer to make sure it was encoded correctly. RFID Reader: A RFID reader is a device that emits radio waves and captures data from UHF RFID tags. Becoming a member also gives you cheaper charging rates which is great if you regularly use one of its units to top-up your car. Dec 22, 2021 · Radio Frequency Identification (RFID) is a wireless, non-contact use of radio frequency waves to transmit data. eXpressbadging. Near Field Communication (NFC) – 13. It will allow us to connect the physical world to the digital world in new and innovative ways. The radio waves then pass through a specially designed interface and are analyzed by targeted computer systems. May 26, 2024 · Also, RFID locks can be distinguished on several bases. Tag The RFID tag has an embedded transmitter and receiver. This guide covers the components, applications, and environmental factors of RFID systems. May 3, 2019 · How does RFID skimming work? RFID or radio frequency identification is a form of wireless communication. a runner) Take an RFID tag and program on it information about the object you want to track (e. RFID tags are small devices that contain an integrated circuit and Jun 12, 2024 · RFID is short for “radio frequency identification,” and as such, RFID tags utilize radio frequency technology. These can communicate wirelessly with each other. It is the same technology commonly used in pet microchipping and passports. 56MHz-frequency RFID from Apr 9, 2019 · How RFID credit cards work. RFID Tag: The RFID tag is the core element of an RFID key fob. Oct 30, 2023 · Meaning, Working, and Use Cases. Oct 6, 2022 · These RFID cards are usually free, although you may need to become a paying member of some networks to be able to order one. A reader consists of a radio frequency module and an antenna that generates a high frequency electromagnetic field. Car RFID tags exchange wireless signals with an RFID reader as soon as the reader senses that the tag is in its range. RFID or Radio Frequency Identification is a form of wireless information transmission that uses radio waves. RFIDs are widely used in our daily tasks, that is why RFID hacking is becoming increasingly common and one of the primary targets for bad Sep 14, 2021 · One photo ID badge enabled with one shared badge technology, used in multiple systems is the ideal ID badge solution! To learn more on how you can take full advantage of RFID and other related badge technologies and integrate them within your organization’s identity programs visit: www. RFID systems usually include RFID readers, RFID tags, and antennas. In this tutorial, we’ll explore the RFID’s origin, families, components, working principle and global frequency allocation. With supply chain visibility and inventory accuracy becoming more important, RFID has gone from An RFID asset tracking system uses electromagnetic fields to transmit data from an RFID tag to a reader. They can help to automate Nov 16, 2022 · How Does RFID Technology Work? On the surface, RFID technology most resembles a merchandise barcode and barcode scanner. g. When a person presents an RFID card or key fob to an RFID reader, the reader scans the card's information and sends it to the access control software for verification. With supply chain visibility and inventory accuracy becoming more important, RFID has gone from “nice to have Before buying an RFID wallet and finding out do RFID wallets work for you, there are some things you need to consider, including the quality and design of the product as well as its part in a larger security issue. It is a small device that contains a microchip and an antenna, which work together to transmit and receive data wirelessly using radio waves. Some RFID tags can be powered by a battery, but many RFID tags aren't self-powered. How does retail rfid Oct 17, 2023 · An RFID (Radio Frequency Identification) reader is a device that uses radio waves to wirelessly communicate with RFID tags or transponders. Radio frequency identification, or RFID, is typically employed using a microchip Oct 17, 2023 · RFID key fobs consist of several key components that work together to provide secure and convenient access control. RFID systems, like all systems involving energy, are governed by the laws of physics. The RFID card contains a microchip that consists of an antenna and a small memory to store data. There are a number of RFID frequencies These labels integrate RFID technology with functions such as moisture or temperature sensing printable labels, enabling advanced data capture and identification capabilities. Put simply, RFID scanners are used to digitally encode labels that can be read by a reader using radio waves. RFID jamming cards are the size of typical credit cards (0. 5 days ago · The basics of an RFID tracking system go something like this: Pick an object you want to track (e. Apr 4, 2024 · The active RFID tags come in two main types: these are transponders and beacons. They consist of an integrated circuit (IC) chip and an antenna that facilitate the transmission and reception of data wirelessly. A long-range RFID skimmer is a device that a fraudster uses to intercept a connection between an RFID chip and a reader. The antenna transmits the data to a reader that converts the radio waves to usable Short for Radio Frequency Identification, RFID is a smart tracking solution used in many industries, such as inventory management, logistics, or retail. And antenna enables the tag to receive and Jan 7, 2024 · RFID blocking is the process of making your RFID-enabled device resistant to unauthorized access. How Does RFID Work? RFID tags contain a small microchip that stores information about the item to which it is attached. RFID Printers are devices that simultaneously print and encode information on RFID inlays or labels. While barcodes require direct scanning, an RFID scanner can read an encoded Oct 24, 2023 · NFC RFID has been used in marketing for over 10+ years in direct mail, outdoor advertising, product packaging, and print media. May 2, 2017 · An RFID reader is a network connected device (fixed or mobile) with an antenna that sends power as well as data and commands to the tags. These technologies reduce the costs of data collection and improve its accuracy. The frequency is modulated to a different frequency and Yes. How does an RFID card work? To understand how an RFID card works, we need to explore the interaction between the card and an RFID reader. The technology is also being used increasingly in access control and security systems. RFID and NFC offer ways to electronically identify people, places and things. Feb 5, 2016 · RF Physics & RFID: A Brief Overview. Jun 24, 2024 · RFID stands for Radio Frequency Identification technology. But, labels and tags are only one part of RFID technology. How RFID Tags Work. Retail organizations typically use RFID for inventory tracking, gaining real-time visibility into stock levels, viewing how goods move through the supply chain, and how inventory leaves the store. RFID gives a person the ability to track and identify inventory in real time. 56 MHz. The microchip's information can then be picked up through the antenna, which is a copper coil. High Frequency: It is one of the leading technologies used in commercial door locks. Most Oct 17, 2023 · RFID tags, also called transponders, are small electronic devices that contain a microchip and an antenna. You can think of it as an invisible barcode. When the RFID card comes into proximity with the reader, the antenna emits radiofrequency signals. Mar 6, 2023 · Mar 6, 2023. As this trend continues, warehouses increasingly depend upon RFID tags and readers to store critical data for cataloging and tracking warehouse inventory. The ability to allow or deny access based on a vehicle having an RFID tag is a valuable way to provide a perimeter or building an enhanced level of security. The RFID reader acts as an access point for RFID tagged items so that the tags’ data can be made available to business applications. You can think of these encoded labels like barcodes, but with greater readability and accessibility. 5 cm) wide x 2. Testing and certification test and certify tag inlays for retail uses and materials for retailer and supplier assurance. UHF RFID is widely used in inventory management, supply chain logistics, and retail applications. The card is passed over the reader, which knows to shoot off some radio waves (how?), and those radio waves are somehow interpreted to be data, such as an rfid card number. Car RFID tags are part of a vehicle access control system with these parts: Car RFID tag. So, an RFID blocking wallet is worth it for that peace of mind that this low-probability attack could be used against you. An RFID tag is a part of RFID technology. As a cutting-edge technology, Radio Frequency Identification employs electromagnetic fields to automatically identify and track tags attached to objects. As they pass the RFID reader, the reader’s energy activates the tag, enabling it to send its information to the reader. Security applications. Radio frequency identification (RFID) is defined as a cutting-edge technology that harnesses radio waves to identify and monitor objects or people effortlessly without physical contact. Residents place the car RFID tag in a visible spot, usually on their windshield. Generally, the larger the area of the tag antenna, the more energy it will be able to collect and the greater read range the tag will have. The RFID systems consists of RFID Reader and a tag which is normally used in identification and tracking of objects. Radio frequency identification (RFID) is a technology that uses tags to track and wirelessly identify objects. . Physics is the study of matter and its motion through space and time, along with related concepts such as energy and force. The chip then uses those radio waves as an energy source to activate a simple circuit. RFID has been around for a long time and is a term used to describe technology that uses radio frequencies for things like scanning items at a grocery store or giving you access to your office via a key fob. Feb 29, 2024 · “The future is about the Internet of Things, and RFID is a key technology that will enable it. Radio-frequency identification (RFID) is a technology that uses radio waves to wirelessly identify and track tagged objects. The Reader and Antenna: The RFID reader consists of an antenna that generates an electromagnetic field. Computer systems can know about things in the real world, collecting information about where they are, how they are used and whether they need attention. Applications include inventory management and supply chain tracking. But we don't think it should be a deciding factor when Mar 6, 2023 · by Michael Keenan. Jun 12, 2024 · Key Takeaway. This process allows companies to track items without physically contacting them. RFID Printers have the ability to print not only humanreadable numbers and information, but graphics Oct 17, 2023 · A typical RFID system consists of several key components that work together to enable the identification, tracking, and management of objects. Like getting into special events, making quick payments, or even tracking lost items. With credit cards, the particular type of RFID technology used is called near-field communication (NFC). RFID is used across industries, typically to track the location and movement of objects, such as items in a supermarket or components in a factory assembly line. These systems keep out unauthorized vehicles that would otherwise In simple terms, RAIN RFID is a passive, battery-free wireless technology that uses a reader to read and write a tagged item, manage the data, and take action. Due to its all-around resistance to external Nov 17, 2022 · Here are some common examples of how companies use RFID in the supply chain. Mar 31, 2023 · RFID technology is the wireless technology used to identify and track objects using radio waves. To delve deeper, RFID systems also are subjected to fundamental electromagnetic principles. It transmits data from a RFID tag to a reader, giving you accurate, real-time tracking data of your inventory. 2. But unlike barcode technology, RFID operates through radio waves and consists of three parts: an RFID tag, an RFID reader, and a scanning antenna. RFID stands for “radio-frequency identification. RFID Frequency Band Allocation. The term RFID stands for Radio Frequency Identification, as the name defines the operation of the device is based on the Radio frequency signals. With your RFID wristband, you just tap your way in, feeling like a rock star! 5. Most RFID tags are passive, meaning that they contain no power of their own. The chip wakes up and trasmits its ID, then shuts down again. The main concepts such as backscatter modulation and energy harvesting i Aug 6, 2022 · The RFID location tracking technology can track the location of an object without the need for any form of human intervention. com or call 800-909-8602. It offers a long read range and high data transfer rates. Here are the primary RFID frequency ranges: Low Frequency (LF) – 125 KHz or 134 KHz. RAIN RFID provides rich, real-time data and insights for Oct 28, 2023 · How Does RFID Technology Work? RFID, or Radio Frequency Identification, technology works through the use of RFID tags, readers, and a networked system. RFID-blocking technology stops thieves from skimming your cards when they RFID operates across different frequency ranges, each suited for specific applications and environments. One distinction is “How does RFID door lock work?” These are the technologies for RFID locks. A small chip -- known as an RFID tag -- is attached to or implanted in an object. It uses electromagnetic fields to identify and track RFID tags. Oct 17, 2023 · How do RFID tags work? RFID tags, also known as transponders, operate through a process of emit-and-respond communication. 25" (5. Jan 11, 2024 · Yes. Toll collection. Auto-ID Technologies. An information ping in every few seconds is what beacons send out. With supply chain visibility and inventory accuracy becoming more important, RFID has gone from Radio Frequency Identification (RFID) has revolutionized the way we interact with technology, transforming various industries from retail and logistics to healthcare and beyond. This enables businesses and consumers to identify, locate, authenticate, and engage with every item tagged with a RAIN RFID tag. At a very basic level, RFID consists of two things: a tag and a receiver. Understanding these components is essential in comprehending how RFID key fobs operate. 1. The RF radiation does two Jul 14, 2022 · An RF encoder included in the printer transmits and encrypts data before sending it to the chip. Example: Imagine you’re at a concert, and there’s a special lounge for VIPs. Introduction to RFID Modules – Construction, Types and Working. The High-Frequency readers of RFID work on 13. Through antennas, RFID readers communicate with tags attached to specific objects, such as When a RAIN RFID reader emits radio waves to access and read a tag chip, the tag’s antenna collects some of that radio energy and channels it to power the chip. RFID tags’ essence could be boiled down to three key elements: a microchip, antenna and a substrate. Jun 1, 2017 · How Does RFID Work? A basic RFID system comprises two parts: the tag, and the reader. Microwave Frequency RFID: Microwave frequency RFID operates above 3 GHz and provides a very long read Oct 17, 2023 · The RFID tag, also known as an RFID transponder, is typically attached to an object or embedded in an ID card, key fob, or smartphone. Jun 24, 2024 · Radio Frequency Identification (RFID) is a form of wireless communication that incorporates the use of electromagnetic or electrostatic coupling in the radio frequency portion of the electromagnetic spectrum to uniquely identify an object, animal, or person. RFID tags can be “inlaid” or stuck to the item as a label. RFID printers can also print the label itself, including any requested information such as a barcode, graphics, or graphics. With their ability to read and process information from a variety of tags RFID or Radio Frequency Identification is a method to remember and recover remote data. The system is activated by a transfer of electromagnetic energy between a radio label and an RFID transmitter. RFID chips are sometimes used in passports, credit cards, and transport passes to allow Mar 16, 2022 · RFID technology works by sending radio waves to tags, which contain electronic chips. May 7, 2021 · Supporting software or services encode tags and process RFID data for end use. While this technology might sound complicated, we assure you that it’s simpler than it sounds. Jun 20, 2024 · An RFID chip is used to exchange information with an RFID reader using radio waves. The scanning antenna puts out radio-frequency signals in a relatively short range. The chip and reader don't have to touch. RFID sensors read the tag data and forward Dec 3, 2019 · How Do RFID-Blocking Wallets Work? People have been concerned about RFID chips for many years now, and not just in credit cards. They create a protective shield around your cards that prevents unauthorized scanners from recording and stealing information stored within the chips. RFID for vehicle access control. The capacitor receives power and sends it to the microchip. RFID tags, also known as transponders, are small electronic devices that contain a Mar 6, 2023 · by Michael Keenan. They can store a range of information, including unique identification numbers, product details, or sensor data. It involves an RFID tag and a transponder. Depending on the RFID chip — active or passive — these radio waves can broadcast from only a few inches to upwards of 1,500 feet. But does that mean that the radio frequency is being reflected back to the reader? What is RFID technology and how does it work? An RFID or radio frequency identification system consists of two main components, a tag attached to the object to be identified, and a reader that reads the tag. The most popular way to achieve this is by getting an RFID blocking wallet — a holder for your cards that is made from materials that interfere with electromagnetic fields. To protect yourself against RFID skimming, you can line your RFID devices with foil or invest in an RFID-blocking jacket or wallet. Jan 28, 2022 · How does RFID work? Many logistics operations of all sizes have recently undergone digital transformations to keep their businesses in step with the competition. These readers are essential components in RFID systems, enabling the retrieval and transmission of data from the RFID tags. ”. Inside the capsule, you'll find the actual silicon microchip that holds the important information, as well as a tuning capacitor and an antenna coil. They can also be a hard tag made of plastic or metal affixed to How Does RFID Work? RFID works by employing an RFID transponder (or tag) and a reader. An RFID label works by transmitting or receiving data through an antenna and integrated circuit often called a microchip. How does RFID work? A Radio-Frequency Identification system has three parts: A scanning antenna；A transceiver with a decoder to interpret the data and A transponder – the RFID tag – that has been programmed with information. Contactless credit cards. The tags contain information that can be read at short range via radio waves. RFID tags are frequently used for merchandise, but they can also be used to track vehicles, pets, and even Apr 22, 2024 · Radio Frequency Identification (RFID): A technology that allows the identification of an item using radio waves. Jun 2, 2024 · RFID or radio frequency identification is a technology that facilitates the wireless discovery and tracking of any object using high-frequency radio waves. These tags are small and can be attached to people, machines, electronic devices, vehicles, or any other physical object. Real-time inventory tracking. It is an easy tap-and-go system. The RFID chips used in credit cards, thankfully, are passive RFID tags, so the chip has to be close enough — usually four to How RFID tags work. ” Marc Benioff, CEO of Salesforce (2011) How does an RFID card work? RFID cards work by emitting a radio signal that a scanner can read. The RFID tag, also known as an RFID transponder or chip, contains a unique identifier and is attached to an object or embedded in a card. Mar 12, 2021 · The different RFID tag types and when to use them. Whereas the tag is Introduction. Putting these components together requires finesse for every retailer’s product and box design—it takes time, commitment, and collaboration. Readers receive these signals and convert them to useful information. Dec 21, 2018 · In this video, we learn about how RFID works and we see how RFID chips are designed. They use a loop similar to the ones used in wireless charging phones to pick up energy from a similar one in the reader, which is rectified and applied to a chip in the tag. Introduction. The actual RFID component contained in a tag has two parts: an integrated circuit for storing and processing information, and an antenna to receive and transmit a signal. When an RFID reader emits a radio frequency (RF) signal, it energizes the RFID tag. The RFID reader is the device responsible for sending and receiving radio waves. It consists of three primary components: RFID tags, RFID readers, and a data management system. Oct 17, 2023 · In the next section, we will delve deeper into how RFID cards work and the components they consist of. An RFID reader is needed to transmit radio RFID skimming is the wireless interception of information from RFID chip-based debit, credit and ID cards and other documents, such as passports. The technology consists of two main components: the RFID card and the RFID reader. These radio waves transmit data from the tag to a reader, which then transmits the information to an RFID computer program. The tag Jan 25, 2023 · In this video, we'll give you a brief overview of Radio-Frequency Identification (RFID) technology. 56 MHz, and the range of reading is 10 centimeters to 1 meter. Fact 1: Quality and Design Matter. With this kind of control, warehouse management can always know where inventory is located within the supply chain. Since its establishment by MIT researchers in 1999, the realm of automatic identification technology, which we call auto-ID for short, has continuously expanded. Radio-frequency identification (RFID) technology is a way for retailers to identify items using radio waves. Oct 17, 2023 · How does UHF RFID work? UHF RFID technology relies on the interaction between RFID readers and UHF RFID tags to enable automatic identification and tracking of objects. Jun 25, 2017 · In this video, RFID (Radio Frequency Identification) Technology has been explained. RFID blocking technology was developed to prevent criminals from taking Jul 2, 2021 · The RFID-related crime that does happen typically occurs at the point of sale when people turn over their credit cards. Whether you are talking about office equipment in a multi-story building, wheelchairs and IV pumps in a large hospital, tools and equipment in a factory, or pumping equipment in far-flung oil fields, RFID can provide accurate, real-time Oct 17, 2023 · Ultra-High Frequency (UHF) RFID: UHF RFID operates within the range of 300 MHz to 3 GHz. Ultra-High Frequency (UHF) – 433 MHz, 860-960 MHz. Liberty Charge, for example, offers membership from £5 per month – with a free RFID card. 9mm thin and measures: 3 3/8" (8. The tags store information about the object, scanners report the data, and software compiles it into a form management can use. Devices like keys, fobs, credit cards, and even passports use RFID technology. How Do RFID Wallets Work? An RFID-blocking wallet functions by using materials like carbon fiber or aluminum to interrupt the electromagnetic signal from the RFID chip. . RFID blocking cards do work. 4 cm) tall), and they work in an active way. Oct 17, 2023 · An RFID (Radio Frequency Identification) system consists of several key components that work together to enable the identification and tracking of objects using radio waves. These components include RFID tags, RFID readers, RFID antennas, and RFID middleware. Sep 7, 2021 · RFID stands for radio-frequency identification, and is a vital part of modern tracking, location, and identification technologies. The chip is attached to an RFID reader (interrogator RFID is a wireless technology that uses radio frequency fields to transfer data. The scanner, or reader, emits radio waves that pick up signals from nearby items Apparently, the RFID reader is composed of two parts: an antenna and an integrated circuit. For gate access control, RFID can be used to automatically identify vehicles and drivers. It contains a microchip and an antenna for communication with RFID readers. the runner's bib number) Attach the tag to the object you want to track. It contains a microchip and an antenna, which enable it to transmit and receive data. The microchip within the tag is what stores and processes information, modulates and demodulates radio-frequency signals. A database contains a list of all products or persons within the system, so when the RFID transponder approaches a receiver, the reader can identify the unique identity of the person or product. They have a signal that is readable from hundreds of feet away. Learn the basics of RFID technology, how it works, what it is used for, and the different types and frequencies of RFID. Apr 23, 2023 · So, let's try it out. In the case of your credit card it is sending the card numbers to the reader to be processed. An RFID enabled credit card can be identified by its unique Wi-Fi-like symbol and a rectangular chip in front. Mar 18, 2024 · Definition. Oct 17, 2023 · How Does RFID Technology Work? RFID (Radio Frequency Identification) technology works through the use of radio waves to wirelessly transfer data between an RFID card and a reader device. Sep 19, 2023 · Nowadays, RFID technology is applied in a wide range of applications including: Access control solutions. The radio label, also called RFID tag, is made up of an electronic chip and an antenna that receives the radio signal emitted by the reader also May 9, 2023 · RFID, or radio frequency identification, is a type of technology that sends information between a tag to a scanner. Depending on the type, the receiver tracks and Sep 30, 2016 · Share. The RFID card, also known as a tag or transponder, contains a microchip and Oct 17, 2019 · It works like this: The RFID system consists of a tracking chip and a control device, which is a reader and a transmitter in one. When a scanner is nearby an RFID chip is activated, sending information to the scanner for reading. gd jf sp da os zv tg wi lw bw