12.125" x 6" x 12.125", 480/277/240/120 VAC 50/60 Hz 0.68/1.18/1.36/2.66 A Primary, 24 VAC 4 A Secondary, 19.2/16.26/17.7/16.61 W, 300 VA Transformer, Overcurrent Protection Circuit Breaker, Enclosed with Low Voltage Compartment, AC Power Supply