Venture Uni-Form Pulse Start, Energy Saving metal halide replacement lamp (open rated). 400W provides the same light as a +400W version, at 95 lumens per watt, ie excellent initial light output and impressive lumen mainatanance throughout lamp life.Lamp DescriptionHIPT 400W/H75/UVS/T52/PS/4KLamp code = 00246Lumen output of 38 000Suitable for horizontal useBase type = E40CRI = 65Bulb designation = T52Warm up = 2-3 minutesRestart when hot = 4-6 minutesControl gear = mercury ballast and ignitorLuminaire type = open or enclosed