High Intensity Discharge (HID) Lamp, Mercury Vapor Lamp Type, 250 Watts, BT28 Lamp Shape, H37 ANSI Number, Lamp Designation HF250XR/H37, Mounting Position VBU, White, For Use With Enclosed Fixtures, 10K Average Life (Hours), Max. Overall Length 8 1/4 In., 13,700 Initial Lumens, 4000 Color Temp., 40 CRI, Case Quantity 6, E39 Base, 10,960 Mean Lumens, Light Center Length 5.00 In.