General Purpose Transformer; Primary Voltage 120 Volt AC; Secondary Voltage 26.5 VOC; Frequency Rating 50/60 Hertz; Power Rating 40 Volt Amp at 24 Volt AC; Temperature Rise -20 to 105 Deg F; Enclosure Type D; Size 2-7/32 Inch Width x 2-15/16 Inch Depth x 3-7/32 Inch Height; Mounting 4 Inch x 4 Inch Plate (Protruding into Junction Box); Application Residential Combustion Control System; Approval UL, CSA, NEC Class 2; Connection Type 9 Inch Lead Wire; Includes Thermostat, Gas Valve, Relay