ACM 125KHz RFID Key Fob Proximity Access Control Tag

The ACM 125KHz RFID Key Fob Proximity Access Control Tag (SKU ACM-KEYFOB-125KHZ, also listed as GR-ACM-KEYFOB-125KHZ-LN) is the part the user carries. RFID means radio-frequency identification: hold the fob near a reader and the reader picks up the fob's ID number.

What each spec means in use

• 125 kHz (kilohertz) frequency: it is read by 125 kHz proximity systems.
• EM4100 / EM4102 compatible: suits readers of this type, including door entry systems, access control keypads and standalone RFID readers.
• Read range 2–10 cm, depending on the reader: you present the fob close to the reader. You don't wave it from across a room.
• Unique pre-programmed ID: every fob has its own number, set at the factory, so the system can recognise each one.
• Waterproof ABS housing: ABS is a hard, durable plastic. The keychain format fits keys, lanyards and ID holders.

What else you need

A fob does not open a door by itself. It needs a compatible reader wired to an access controller. The reader passes on the ID, the system checks it, and the connected door controller grants entry.

Typical settings are office buildings, residential access, parking access, security doors and employee identification. Work out how many people need credentials before you order, as each fob carries one fixed ID.