iPower GLBLST600D Horticulture 600 Watt Digital Dimmable Electronic Ballast for Hydroponics HPS MH Grow Light, 600W
Amazon.com: VIVOSUN 1000 Watt Dimmable Electronic Digital Ballast with Enhanced Internal Cooled Fan, 25% Less Heat Generated and 15% Longer Service Life : Patio, Lawn & Garden