Each keyfob has a unique ID number and you can assign a user ID to each keyfob for identify who used it.
Like Prox Cards, if you lose the keyfob, remove the keyfob from the M1 system. Just like access control keys. When an employee quits, take them out of the system.
On the Caddx system you can have up to 48 keyfobs, but are limited to 8 push button operations. 4 main buttons on the keyfob, plus two - 2 button push modes.