Sylvania Metalarc® Pro-Tech® Metal Halide Lamp, MP250/BU-ONLY, 250 W, 133 VAC, Quartz Metal Halide Lamp, EX39 Exclusionary Mogul Lamp Base, BT28, 23000 Lumens, 10000 hr Average Life, 65 CRI, 4000 K Color, Clear Lamp, Probe Start, Open Fixture, 3.504 in Dia x 8.31 in L