Advance Centium Electronic Fluorescent Ballast, 54 W Lamp, 44 to 118 W Wattage, 120 to 277 V AC, 0.16 to 0.42 A, 50/60 Hz Frequency, Programmed Start, -20 deg F Minimum Starting, Total Harmonic Distortion: 10 %, Power Factor: >0.98, No Dimmable, 2 Lamps, Thermal Protection: Class P, Ballast Factor: 1, NEMA 34 Enclosure, 70 deg C, Metal, 14.17 in L x 1.18 in W x 1.06 in H Dimensions