Uxl-450so, xe 450w, 450 watt, 18volt, 2000 hour rated bulb with base. ushio uxl short-arc xenon gas discharge lamps feature a continuous wavelength spectrum that closely approximates daylight color temperatures and have strong color rendering characteristics. Uxl lamps are used for a variety of scientific, analytical and medical illumination purposes including spectrophotometry, solar simulation, microscopy, handheld searchlights and surgical lighting.