Lionel KW Transformer 190 Watt 2 Train Transformer with Whistle ~ 1950 $125, shipping included (US Only) Second largest Postwar Era transformer in the Lionel line and with a variety of nice features, including dual controls, whistle and direction controls for both controllers, a circuit breaker with overload light, fixed voltage outputs for accessories and a streamlined casing. The three fixed voltage outputs are 6 volts, 14 volts, and 20 volts. The KW is among the most reliable of Lionel's transformers.