Compact, quiet, and lightweight, these 400-, 600-, and 1000-Watt Electronic Ballasts reduce energy consumption -and cost- operating via digital circuits rather than traditional magnetic coils. These versatile ballasts fire both metal halide and high presure sodium lamps and their consistent wattage output coupled with a start-up safety feature optimizes lamp discharge and prolongs the life of lamps. 120-and 240 volt ballasts include a detachable power cord and socket assembly. 400- and 600-watt ballasts have a two- year warranty and an option to purchase a third year from the manufacturer. The 1000- watt ballasts come with a one-year warranty.