This pack of 100 UHPPOTE Proximity TK4100 125khz RFID Id Card Keyfobs are made with ABS material, making them waterproof and durable. Each keyfob is pre-programmed with a unique digit ID number and comes attached with a metal key ring. These keyfobs are perfect for access control systems, video door phones, electric locks and more. They are compatible with standard EM ID access devices and ID readers, but not with UHF readers or encrypted readers such as HID, Cobra, APCiK, Paradox, Radio, Honeywell, Kaba, Isonas, etc. Unlock your door with ease and convenience with these UHPPOTE Proximity TK4100 125khz RFID Id Card Keyfobs in blue.