The RailPower 1300 Model Train Throttle Control Transformer is a black HO gauge transformer by MRC. It is pre-built and analog-controlled, with a power type of DC and a voltage of 120V. The item measures 6 1/2 inches in length, 5 inches in width, and 2 inches in height. It is made of plastic and designed for HO gauge model railroads and trains. Not sure of the working condition, is from my father's estate. light turns on when  you plug it in. Looks to be in great condition. see pictures.