Ceramalux HID Lamp, MH R 400W/640 E39 ED37 U, 400 W, 135 V, 3.25 A, Metal Halide Lamp, Single Contact Mogul E39 Lamp Base, ED37, 25350 lm, 20000 hr Average Life, 65 CRI, 3900 K Color, Switch Start, M59/E Ballast, Enclosed Fixture, Cool White/Clear, 4-5/8 in Dia x 11-1/2 in L, 98 lm/W Efficacy, 400 deg C Bulb, 210 deg C Cap-Base, Standards/Approvals: ANSI M59/E Specified, Applications: For general lighting