... harmonicGeneral harmonic THD≤ 10%High light efficiencyand energy saving.Low power consumptionMore lumens: 20-30% more lumens than magnetic ballastsConstant output ... .Completely silent: no more humming and buzzing.Constant output of power when voltage fluctuate with no flickeringNo fans inside,water resistance ... (97mm) H: 34 in (135mm) UL,CUL, CE,TUV, listed 120-240V,1000W,600W,400W, digital ballast