GE, MVR400/U/CP, 400W, Clear Multi-Vapor Metal Halide Lamp, ED37 Bulb Shape, Universal Burn Position, Mogul Base, MOL=11.5, 20,000 Hour, 36000 Lumens, 4000 Kelvin Color Temperature, CRI=65, M59 ANSI Ballast Type, 90% @ 50% Of Life Lumen Maintenance, Universal Burn Position, For Open Or Enclosed Fixtures.