The GE MVR250/U 250W Quartz Metal Halide rated to last an average of 10,000 hours and emits 20,800 Initial Lumens. The GE 42729 Multi-Vapor R250 has an (E39) mogul Base and features a nice bright white 4200K color spectrum temperature. General Electric's 250W Quartz Metal Halide lamps have an ANSI code M58/E and can be used in enclosed fixtures only.