High Intensity Discharge (HID) Lamp, High Pressure Sodium, 100 Watts, ED23-1/2 Lamp Shape, ANSI Number S54, Lamp Designation LU100/H/ECO, U Operating Position, Universal Mounting Position, Description/Special Features Clear, For Use With Open or Enclosed Fixtures, Average Life 24K hr., Max. Overall Length 7-1/2 In., 9500 Initial Lumens, 2000 Color Temp., 22 CRI, Mogul Base, Open Fixture Type, 8550 Mean Lumens, Light Center Length 5 In., Standards Meets 2012 Lighting Legislation Energy Standards