Pulsetek™ HID Lamp, MP400W/V/UVS/PS/740 STD, 400 W, 135 V, Metal Halide Lamp, EX39 Lamp Base, ED37, 41000 lm, 20000 hr Average Life, 68 CRI, 4000 K Color, Pulse Start, Enclosed Fixture, Clear, 4-5/8 in Dia x 11-1/2 in L