Luxrite LR20675 (10-Pack) MH400/U/ED37 400-Watt HID Metal Halide Light Bulb, Cool White 2100K, 36000 Lumens, E39 mogul base Color/Finish: Cool White Color Temperature: 4,000K Average Lifetime: 15,000 Hours Lumens (light output): 35000 E39 mogul base