... ,277V,120-240V availiable, 50-60HZInput power:1000W,600W,400W,250W avaliable Dimmalble electronic for hydroponics and horticulture,With or without fanS ... ballast is considerably cooler in the operation than the old ballasts making it far easier to maintain cool growing conditions for ... is silent in operation .Say goodbye to all that humming 1000W electronic ballast hps mh