The Lionel Type ZW Transformer was the largest that was issued during the post war period. The one listed here has 250 watts of available power and was produced in 1948-49. This transformer can operate four individual trains on four variable voltage circuits, however the two inner controls are often used for accessories and these have no whistle or directional controls. It has both power and short circuit light indicators. Serviced and checked on my personal layout I have installed new 40 W whistle diodes  carbon rollers, and T V S Diodes on the power terminals. I guarantee it to be as represented. My T C A # 20-75043.               1438