... HPS/MH electronic ballast 400W, 600W, 1000W,110V/240V dual voltage MH/HPS compatible UL,CUL,CE,TUV listed No fans inside HPS/MH electronic ballast.Welthink series digital electronic ballast can run HPS and MH ... features of the Welthink series HPS/MH electronic ballast.Run for HPS and MH lamps both.High power factorPF≥0 ... CUL CE TUV listed HPS/MH electronic ballast,250W,320W,400W,500W 600W, 800W,1000W