Let’s see what we know. It’s apparently an active device......a transmitter of some sort that use IR (infrared) beams to interact with something. He also mentioned it has been modified to work with UV (ultraviolet) light....odd.
He mentioned it “wields power” and it works with deviceS as in more than one.
The front of it looks to have a slide switch in the middle and I assume that is the activation switch. With a slide switch like that (instead of a push button momentary contact switch) it appears that you switch the device on, and it stays on.
There also seems to be an LED on the front in the lower corner near the switch. Some sort of power indicator maybe? It also appears to have been designed to lay flat on a surface instead of being held.
So, what is that size, can be turned on for constant activity, has to be placed on a flat surface, and works with IR or even UV light?
Is it a trigger for a trap of sorts. If something crosses in front of it and breaks the beam, the trap is sprung on the far end? Maybe a far out electronic rat trap of sorts?