I'm not sure exactly how this works but the disc spins around.
The is a lens on top, in good shape, I'm not sure what's that's for either.
There are tow pieces on the front that have hinges.
Metal has not been cleaned or polished. There is some oxidation on the back and the glass is foggy.
It measures: almost 3.5" long x 2 3/8" wide x 1.5" deep.