The SYLVANIA 47739-4 metal halide ballast features a four-tap voltage input for compatibility from 120 to 277 volts. For use with 400-watt lamps, this metal halide ballast boasts a high power factor of 90 percent, ensuring maximum efficiency. A temperature rating of 212 degrees Fahrenheit makes the ballast suitable for mounting in warehouses and manufacturing facilities where high heat may be an issue. This ballast kit comes complete with a dry capacitor and bracket kit. The ballast itself is designed to operate one metal halide lamp of 400 watts and comes with a two-year warranty for the ballast.