... 400W, 600W, 1000W,110V/240V dual voltage MH/HPS compatible UL,CUL,CE,TUV listed No fans inside HPS/MH electronic ... hang the lamp, no need any external starter and compensation capacitor.Completely silent: no more humming and buzzing.Constant output of ... resistance and maintenance free operationSoft startingDimming function is option.Approval: UL,CUL, EMC, ROSH,CE,TUV.Suitable Bulbs400W, 600W, 1000W ...