Help with a Western Electric Rectifier Please

I bought a Western Electric "Rectifier" and would like to know what it's purpose is and whom would use it. It is not tube driven. It's self contained in a metal case and has a capacitor, transformer (and others) and a power cord along with two alligator clips (black and red). Any help would be appreciated, I'm a novice on electronics. Is this an audio or telephone related item?