GE Ecolux® Lucalox® High Pressure Sodium Lamp, High Intensity Discharge, LU400/H/ECO Designation, 400 W Wattage, 198 VAC, High Pressure Sodium Lamp, E39 Mogul Screw Lamp Base, ED18 Shape, 51000 Lumens, 24000 hr Average Life, 22 CRI, 2100 K Color Temperature, Clear Lamp, S51 Ballast, Enclosed/Open Fixture, 2-1/4 in Dia x 9-3/4 in L Dimensions