RaceHorse, Electronic, CFL Ballast, Ballast Start Type Rapid, Input Voltage 120 to 277V AC, Number of Bulbs Supported 1, 2, Max. Bulb Watts 18 W, 28 W, 38 W, 39 W, Ballast Bulb Type BX, T5, T5HO, Dimming No, Dimming Type No Dimming, Dimming Method No Dimming, Dimming Range No Dimming, Min. Starting Temp. -22 Degrees F