[Waterproof ABS Material] The RFID key tag is made of high-quality ABS material. The shell is strong and durable, with good waterproof, shockproof, and anti-corrosion performance, allowing for reliable use in various environments. After multiple manufacturing processes, the product quality is well guaranteed. Available in red and blue colors for added choice.[Comes with a Portable Key Ring] Each tag comes with a key ring, making it easy to attach to keys or other items for convenient use and to prevent loss. The key tag measures 3.3 x 2.9 x 0.6 cm, is compact, and easy to carrycan be stored in pockets or backpacks. Its ergonomic design enhances daily usability.[TK4100 Chip] The RFID sensor ID card uses the TK4100 chip, operating at a frequency of 125 kHz. It is compatible with standard ID access control devices. Each chip has a unique ID number permanently stored in the chip and printed on the back of the tag for identification.[Read Only & Easy to Read] The chip is read-only and cannot be rewritten or programmed. It does not support UHF or encrypted systems. This RFID key tag works with 125 kHz card readers, with an effective reading distance of 010 cm.[Good Helper for Access Control System] This RFID key fob is suitable for various applications such as access control systems, hotel door locks, employee attendance, school campus access, identity verification, security systems, parking access, and timekeeping systems. Ideal for use in offices, homes, schools, residential communities, and other locations requiring secure access.Support: Read Only, Not Writable Working Frequency: 125 kHz Size: 29 x 33 x 6 mm Material: ABS Color: Blue, Red Package Contents: 50 x 125 kHz RFID Key Tags Note: Light and display settings may cause slight color differences between the image and the actual item. Measurement allows for an error of +/- 13 cm.