Portable Access Card: Our access control key card is very small and light. Each RFID transponder is also equipped with a small metal ring, which allows you to hang on keychains, backpacks and other items, which is more convenient to use and prevents loss. RFID, EM4100 Chip: Our chip type is TK4100/EM4100. The NFC APP tool can be used to write the chip of the RFID key fob. The access control key card is easy to set up, equipped with advanced technology and responsive. It can detect within 10 cm, which works 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 dense plastic shell encloses the chip inside, which is waterproof, shockproof and corrosion resistant. The chip is read-only: Each read-only RFID chip has its own ID, which is 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 badge can be used in various places, 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.