... 320W, 400W,500W, 600W,800W,1000W CE,TUV,UL,CUL,GS approved No fans HID electronic ballast 250W,320W, 400W,500W, 600W,800W ... , our electronic ballast have more advantages: · Small in volume, light in weight,only 30% volume and weight of magnetic ballasts,· 30 ... maintenance cost.· More lumens: 20-30% more lumens than magnetic ballasts· Constant output of power· Protection functions: Open circuit and short ...