High Pressure Sodium HID Bulb, Bulb Base Type Mogul Screw (E39), Bulb Dia. 2 1/4 in, Bulb Housing Glass, Bulb Shape ED18, Color Rendering Index 26, Color Temperature 2100K, Lumens 28,500 lm, Light Technology High Pressure Sodium, Overall Length 9 3/4 in, Shatter- No, Voltage 110V, Watts 251 W, Bulb Beam Angle 360 Degrees , Bulb Finish Clear, Rated Life 24,000 hr, ANSI Code S50, Dimmable No, For Enclosed Fixtures Yes, Bulb Operating Position Universal Burning