Lamp, Shatter-Resistant, Mercury Vapor, CDM145/BU/0/4K/ED28 (PK X 12), 145 Watts, 125 Volts, 13775 Initial Lumens, 4000 K, 87 CRI, ED28 Shape, 3.5 IN Dia, 8.31 IN Long, ED28 Bulb, Exclusionary Mogul (EX39) Base, 20000 Avg Life Hrs, 940 Color, PFA Coating