... inside ul certified electronic ballast, electronic grow ballast. Welthink series grow light digital, electronic ballast can run ... 100V~240V,277V,347V 400VThey have been widely used in hydroponics, horticulture, greenhouse and hobby gardening ... ,etc. The features of the Welthink series Grow light ballast,digital ballast.Run for HPS and ... (135mm) UL,CUL,CE,TUV,approved hydroponic grow lights ballast