If you need more than just a single fob, for whatever reason. That’s just good old fashioned common sense.
Optical pairing is a Bluetooth® pairing method developed by Mighton Products Ltd as a form of Bluetooth® out-of-band pairing.
It is known to be secure against ‘man-in-the-middle’ attacks due to it’s inherent privacy, made possible by the close physical proximity and the single ‘point to point’ procedure.
It works by communicating one of the Bluetooth® pairing encryption keys through a ‘light flashing pattern’ from one device to the other. When optical pairing, only the devices that participate will communicate with each other.