HID Metal Halide Lamp, Designation: MP320/ED28/PS/BU/4K, 320 WTT, ED28 Shape, E39 Mogul Base, Clear, 20000 HR, Lumens: 31000 LM Initial, 4200 DEG K Color Temperature, Cool White 65 CRI, 8-5/16 IN Length, 3-1/2 IN Diameter, Burn Position: BU +/- 15