Metal Halide Lamp, 65, 4000 K, 33100 LM (Horizontal);36000 LM (Vertical) Brightness (Lumens), 400 W, Clear, Hard Glass Material, 15000 H (Horizontal);20000 H (Vertical) Average Life, Mogul Base, M59 Ansi Ballast Code, Non Dimmable, 4.62 In Diameter, 11.5 In Height, 61.11 % Mercury Content, 4.45 LB