ReVolt Digital Ballast for HPS/MH Bulbs, 400-watt Dimmable (Run ballast at 50; 75; or 100-percent power setting); 30-percent Lumens increase (and 30-percent power savings) over Magnetic Ballasts Runs cool and quiet; Compact; lightweight design; Maximum Lumens with either HPS and MH Bulbs Worldwide Voltage Input n 100V-268V (50-60Hz); Universal Lamp Cord Receptacle Fast startup; stable light output; and longer bulb life; Generator and Flip Box Ready 3 Year Bumper to Bumper Warranty