High Intensity Discharge (HID) Lamp, High Pressure Sodium, 50 Watts, B17 Lamp Shape, ANSI Number S68, Lamp Designation LU50/MED/ECO, U Operating Position, Universal Mounting Position, Description/Special Features Clear, Average Life 24K hr., Max. Overall Length 5-7/16 In., 4000 Initial Lumens, 1900 Color Temp., 22 CRI, Medium Base, Open Fixture Type, 4000 Mean Lumens, Light Center Length 3-7/16 In., Standards Meets 2012 Lighting Legislation Energy Standards