[Durable & Waterproof ABS Material] Crafted from high-quality ABS, this RFID key fob is built to last. Its robust shell offers excellent waterproof, shockproof, and anti-corrosion performance, ensuring reliable use. Undergoing rigorous testing, its quality is guaranteed. Choose from red or blue for added personalization. [Portable Keychain Included] Each tag comes with a convenient keychain for easy attachment to keys or other items, preventing loss. Compact in size (3.3x2.9x0.6 cm), it easily fits in pockets and backpacks, making it ideal for everyday carry. [TK4100 Chip] Equipped with a TK4100 RFID sensor ID card chip operating at 125Khz, select the appropriate access card for your needs. Compatible with standard ID access devices. Each chip has a unique ID stored within and printed on the tag for enhanced security. [Read-Only & Easy to Read] Please note: This tag is read-only and cannot be programmed. It is not compatible with UHF or encrypted technologies. Suitable for 125KHZ card readers with a reading distance of 0-10 cm. [Ideal for Access Control Systems] This RFID key fob is versatile and suitable for various applications, including access control, hotel locks, employee attendance, school campus visits, identity recognition, security systems, parking access, and timekeeping. Perfect for offices, homes, schools, communities, and any environment requiring a secure access control system. Supports: Read only, not writable. Working frequency: 125KHZ Size: 29x33x6mm Material: ABS Color: blue, red