HID Ballast, Lamp Type Metal Halide, Lamp Watts 250, ANSI Code M58, Input Watts 286, Input Voltage 120/208/240/277, Ballast Type Probe Start, Ballast Family HID Magnetic, Number of Lamps 1, Min. Starting Temp. -20 Degrees F, 60 Hz, 2.3 Operating Amps @ 120V, 1.4 Operating Amps @ 208V, 1.2 Operating Amps @ 240V, 1 Operating Amps @ 277V, Insulation Class H, No Thermal Protection, Length 3-15/16 In., Width 4-3/8 In., Height 2-13/16 In.