HID Corporation 1346 ProxKey III Key Fob Proximity Access Card Keyfob, 1-1/4" Length x 1-1/2" Height x 15/64" Thick (Pack of 1) Small enough to fit on a key ring Universal compatibility with HID proximity card readers Provides an external number for easy identification and control Can be placed on a key ring for convenient entry Supports formats up to 85 bits, with over 137 billion codes Lifetime warranty