[Waterproof ABS Material] The RFID key tag is made of high-quality ABS material, with a strong and durable shell that offers good waterproof, shockproof, and anti-corrosion performance, ensuring reliable use in various environments. After multiple manufacturing processes, product quality is assured. Available in red and blue colors for added choice. [Comes with a Portable Key Ring] Each tag includes a key ring, allowing it to be attached to keys and other items for easy use and to prevent loss. The key tag measures 3.3 x 2.9 x 0.6 cm, making it compact and convenient to carry in pockets or backpacks. Its rounded shape enhances usability for daily applications. [TK4100 Chip] This RFID key tag features a TK4100 chip operating at a frequency of 125 kHz, compatible with standard ID access control systems. Each chip has a unique factory-programmed ID number stored permanently and printed on the back of the tag for identification purposes. [Read Only & Easy to Read] The chip is read-only and cannot be rewritten or programmed. It does not support UHF or encrypted formats such as HID, Radio, Cobra, Mifare, APCiK, Indala, Isonas, or others. The waterproof RFID key tag works with 125 kHz card readers, with a reading distance of up to 10 cm. [Good Helper for Access Control System] Suitable for use in various access control applications including door locks, hotel systems, employee attendance, school campus access, visitor management, identity verification, parking access, and timekeeping systems. Ideal for 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: Lighting and display differences may cause slight variations in color between the image and the actual item. Measurement allows an error of +/- 1-3 cm.