The Kichler Lighting 15MHS100AZT Steel HID Single Metal Halide Ballast provides proper starting voltage to strike. They maintain the fixture"s high intensity arc and regulate current to the lamp during operation for pure, consistent quality of light. Finished in textured architectural bronze to complement Kichler"s landscape fixtures as well as blend in with the natural surroundings of your landscape. Above ground ballasts carry a UL listing mark suitable for the US and Canadian marketplace. Maximum distance from lamp to ballast cannot exceed 15-feet.