The Scintilla Multivolt A.C. Sub-Station (Model S100) is a transformer designed for model railroads and trains. This AC power type sub-station allows for efficient voltage conversion and control, making it a crucial component for powering and managing the electrical needs of a model railroad setup. With its multivolt capabilities and specifically designed model, this sub-station ensures a reliable and consistent power source for a wide range of model railroads and trains.