Advance High Pressure Sodium Ballast, Core/Coil HID Magnetic, High Pressure Sodium Lamp, 100 W Lamp, 135 W Wattage, 120/208/240/277 VAC, 1.15/0.67/0.58/0.5 A, 60 Hz Frequency, Pulse Start, -40 deg F Minimum Starting, Power Factor: 1, No Dimmable, 1 Lamp, Thermal Protection: Class P, 71A8091 Lamp Base, Ballast Factor: 1, ANSI S54 Ballast Grade, 4 in L x 3.45 in W x 2.9 in H Dimensions