Keystone Technologies Electronic Fluorescent Ballast, T8 Fluorescent Lamp, 120 to 277 VAC, 50/60 Hz Frequency, Instant Start, 0 deg F Minimum Starting, Total Harmonic Distortion: 10 %, Power Factor: 0.95 to 0.99, Ballast Factor: 0.88 to 1.05, 9 in L x 2.15 in W x 1.61 in H Dimensions