For double the lighting power and increased control, try the Lutron H3DT817GU210 dimming ballast. This fluorescent ballast accommodates two lamps in a sleek flicker-free design. Each Lutron H3DT817GU110 ballast has a dimming range of 0.7 to 100 percent. Its five-year warranty means five years of completely worry-free use. The 120-277 volt Lutron dimming ballast includes programmed rapid start technology to provide a shorter startup time.