OSRAM HSD short arc metal halide lamps are ready to meet the demands of any stage, architectural or event lighting application. These Metal Halide lamps are available in various configurations, each of which offers high lumen output in combination with crisp daylight color temperatures in the range of 5600 to 7800K. HSD lamps are ideal for large scale architectural lighting applications where both maximum output and long service life are important. "Metail Halide HSD lamps" are single-ended, with an outer jacket for ease of handling. Please Note: This bulb has a longer life and higher color temperature then item # 54311 as long as you use it with electronic ballast. This bulb is not recommended for use with electronic ballast only, Osram will not guarantee the life if used with magnetic ballast.