2015 Nanolux 600w DUAL Digital Dimmable E-Ballast MH HPS Grow Light This ballast will run fire TWO bulbs simultaneously at 100%, 75%, or 50% Measurements: 18"L x 4"W x 2.5"H, Weight : 8 lbs Voltage: 240v, Easily switches between MH and HPS Bulbs Modular power cord included, Universal lamp receptacle 2 Year Bumper to Bumper Warranty