Metal Halide HID Bulb, ED37 Bulb Shape, Mogul Screw (E39) Bulb Base Type, Metal Halide, 39,000 lm, Bulb Operating Position Universal Burning, 400 W, Trade Number MH400/U, Rated Life 20,000 hr, Standard Bulb Type, 4000K, 360 Degrees Bulb Beam Angle, 4 5/8 in Bulb Dia., 11 1/2 in Overall Length, Shatter- No, Bulb Finish Clear, Color Rendering Index 65, Bulb Minimum Starting Temperature -40 Degrees F