The MRC HO Train Pack Control Transformer Model 100 is a pre-built analog transformer designed for model railroads and trains. With a gold color and a scale of 1:87, this 100W transformer is perfect for controlling HO gauge trains. It features a DC reverse switch for added versatility and is made in the United States by MRC. This ready-to-go transformer is 5 inches in length, 2 inches in height, and 4 inches in width, making it a compact and efficient power supply for your train setup.