Features - U.L. Listed to U.S. & Canadian Standards - Pure Sine Wave Power Signal - (2) 21 Volt Variable Track Outputs - (1) 14 Volt Fixed Output - (1) 10 Volt Fixed Output - Internal Cooling Fan - On/Off Power Switch - Power and Overload Indicator Lights - Compatible As A Power Source For All O Gauge AC-Powered Locomotives & Accessories - Circuit Breaker Protection For Each Output - Voltage LED Displays - Amperage LED Displays - Unit Measures:8 3/4 x 14 3/4 x 11 1/8 WARNING: CHOKING HAZARD - SMALL PARTS! NOT INTENDED FOR CHILDREN UNDER 3.