Electronic Dimmable Ballast 1000W for MH/HPS 1. Has a 99.9% power ... for MH/HPSKey Word: Electronic Ballast, Dimmable Electronic Ballast, Grow Light Ballast 400W, Hydroponic grow ballast 400w, electronic ballast 400w, 110V, UL Listed 1) Input ... ) Current crest factor: <1.5 7) Max. Lamp distance from ballast: 15m/49ft 8) Ambient temperature: -25 ~ +50 Centigrade 9) Enclosure ...