GE Multi-Vapor® PulseArc® Metal Halide Lamp, High Intensity Discharge, MVR320/VBU/HO/PA Designation, 320 W Wattage, Quartz Metal Halide Lamp, E39 Mogul Screw Lamp Base, ED28 Shape, 31000 Lumens, 20000 hr Average Life, 65 CRI, 4000 K Color Temperature, Clear Lamp, Pulse Start, Enclosed Fixture, 3-1/2 in Dia x 8-1/4 in L Dimensions