GE's Multi Vapor metal halide high intensity discharge light bulbs provide long-lasting performance and good efficacy. The sparkling white light provides very good color rendition versus GE's Mercury Vapor high intensity discharge light bulbs. These HID light bulbs and rated to last 20, 000 hours in vertical applications and 15, 000 in horizontal applications. Use this 400-Watt Multi Vapor ED37 shape light bulb only with M59/S ballasts in downlighting, corridors, lobbies and walkways in retail, commercial and industrial applications.