This 100-pack of UHPPOTE Proximity 125KHz RFID EM-ID Card Keyfobs for Door Access Control is the perfect solution for your security needs. Each card is pre-programmed with a unique ID number, with the first 10 digits printed on the card. These keyfobs are read only and unrewritable, and are compatible with standard EM ID access devices or ID readers. However, they cannot support HID, UHF readers, or encrypted readers such as HID, Indala, Cobra, APCiK, Paradox, Radio, Honeywell, Kaba, Isonas, Schlage, etc. With these blue keyfobs, you can rest assured that your security needs are met.