125kHz KeyFobs

Features:

• 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.
• Using HID's ProxProgrammer®, card vendors can ship proximity keyfobs, custom programmed to
  their customers' requirements, from their own inventory. Enables smaller order
  quantities and overnight delivery. (Check with vendor for availability.)
• Lifetime warranty.