Galaxy? Commercial 1000 watt 120-208-240 volt ballast can operate a 1000 watt HPS, MH or DE lamp at 50%, 75%, 100% or 110% settings. The Galaxy? Commercial ballast comes prewired with a Sun System? lamp cord receptacle. It is compatible with all Sun System? brand reflectors. Includes a 6 ft 208-240 volt power cord. 120 volt power cord sold separately. Efficient >98% PF operates 1000 watt HPS/MH and DE lamps, smart start feature, fully sealed extruded aluminum housing, lightweight and quiet operation. Compliant with FCC Article 18 Part A (governs commercial use) as tested by an independent US testing lab in a true as used configuration. Operates at 72 kHz.