Sylvania QUICKTRONIC® HELIOS™ Electronic Dimming Ballast, DD/E Lamp, 26 W Lamp, 53/12 W, 120 to 277 VAC, 0.44/0.19 A, 50/60 Hz, Programmed Rapid Start, 10 deg C Minimum Starting, Total Harmonic Distortion: <10%, Power Factor: >0.98, Yes Dimmable, 2 Lamps, Thermal Protection: Class P, Ballast Factor: 1 to 0.03, NEMA 1, 75 deg C, 4.95 in L x 2.93 in W x 1.35 in H