iPower Denova 1000W Double Ended Digital Dimmable Electronic Ballast for HPS MH Bulbs Grow Light System Kits for Indoor Plants 240V Dimmable and Optional Power Output: 600W, 660W, 1000W, 1150W; 15% more light featuring High Frequency Drive Technology Compatible with Philips Master Green Power Plus, Ushio Pro Plus, AUVL HPS and all Double Ended HPS and MH lamps Backward Compatible with all single-ended HPS and MH lamp bulbs Zero Acoustic Resonance; Fan-less Silent Operation. UL listed and FCC certified; 3-year warranty You need to use a RF protection cord when you want to coordinate the ballast with the reflector to block non ionizing electromagnetic radiation in radio frequencies