Sun System 6 switchable HPS-or-Metal Halide grow light features the Cool Sun 24"x20.5"x7.5" horizontal reflector with 95% reflective aluminum interior, integrated 6 inch air cool fittings and tempered glass lens is the ultimate combination of cooling and peformance. Air passes easily through both ends of the reflector directly over the lamp for maximum inline air cooling. Cool Sun accepts all size Metal Halide and HPS lamps except BT56. 5-year rebuilt or replace warranty.