The Lionel 77 Watt Transformer with wall pack is a pre-built unit designed for model railroads and trains. This analog control system operates on AC power at 115V, with a scale of 1:48 and a gauge of O. The black transformer is made of plastic and is suitable for hobbyists aged 17 years and up. With 77 watts of power, this Lionel transformer is a reliable and essential component for running your model train layout smoothly. sold as is no return.