Central Scientific Co. CENCO Vintage Photoelectric Demonstrator

Description

Here we have a
Central Scientific Co. CENCO Vintage Photoelectric Demonstrator
Powers on and buzzes... other than that I have no idea how to use it or what it does.
I am guessing it is for demonstration of Photoelectric stuff  ( I worked that out all by myself LOL ) I must be a genius :O)
Therefore, as I cannot tell you if it is working as it should or not , it is sold AS IS with NO Returns.
Please see pictures for cosmetic condition
Thank you for looking