Pulse Start Metal Halide Base Up, Bulb Base Type Mogul Screw (E39), Bulb Dia. 3 1/2 in, Bulb Housing Glass, Bulb Shape ED28, Color Rendering Index 68, Color Temperature 4000K, Lumens 42,000 lm, Light Technology Metal Halide, Overall Length 8 1/4 in, Shatter-Resistant No, Voltage 150V, Watts 400 W, Bulb Beam Angle 360 Degrees , Bulb Finish Clear, Rated Life 20,000 hr, ANSI Code M155/M135/E, Dimmable No, For Enclosed Fixtures No, Bulb Operating Position Vertical Base Up +/-15 Degrees