NaturesSunlite&trade; FML 55 watt 5500K, 96 CRI True Color, True Full Spectrum, High Definition 5500K, 96 CRI Full Spectrum Solutions Replacement for UltraLux # UL59155E Sun Light Simulating Excellent for Color Corrective Lighting Fits All lamps, and fixtures that use FML 55 watt 4 tube Does not work in Sunbox light boxes