【Portable Access Card】: Our access control key fob is incredibly small and lightweight. Each RFID transponder also comes with a small metal ring, allowing you to attach it to keychains, backpacks, and other items for convenient use and to prevent loss. 【RFID, EM4100 Chip】: Our chip type is TK4100/EM4100. The NFC APP tool can be used to write the chip on the RFID key fob. The access control key card is easy to configure, equipped with advanced technology, and responsive. It can detect within 10 cm, working perfectly in daily use. 【Waterproof ABS Material】: The RFID key fob is made of high-quality ABS material, and the plastic shell is durable, lightweight, and portable. The tight plastic shell encloses the chip inside, making it waterproof, shockproof, and corrosion-resistant. 【Chip is Read-Only】: Each read-only RFID chip has its own unique ID, making it more secure. It does not support HID and is not compatible with UHF card readers and encrypted card readers such as Kaba, Radio, Cobra, HID, APCiK, Indala, Isonas, Honeywell, Paradox, etc. 【Suitable for Many Scenarios】: The programmable 125kHz RFID tag can be used in various locations, suitable for access control, hotel locks, employee attendance, campus tours, identification, security systems, parking access control, attendance systems, etc. It can also be used as an emergency chip for children and the elderly.