Metal Halide HID Bulb, Bulb Base Type Mogul Screw (E39), Bulb Dia. 3 1/2 in, Bulb Housing Glass, Bulb Shape ED28, Color Rendering Index 62, Color Temperature 4100K, Lumens 30,000 lm, Light Technology Metal Halide, Overall Length 1 in, Shatter- No, Watts 320 W, Bulb Beam Angle 360 Degrees , Bulb Finish Clear, Rated Life 20,000 hr, ANSI Code M154/M132/E, Dimmable No, For Enclosed Fixtures Yes, Bulb Operating Position Universal Burning, Indoor/Outdoor Usage Indoor/Outdoor