Sylvania 21397 - CF42DT/E/IN/830/XL/ECO Triple Tube 4 Pin Base Compact Fluorescent Light Bulb SYLVANIA 42w GX24q-4 3500K 26000 hrs. Fluorescent Bulb EXtended Long average rated life of 26,000 hours at 3 hours per start and 30,000 hours at 12 hours per start Improved lumen output vs.non-amalgam triple tube lamps Operates on electronic ballasts systems Flicker-free starting and dimmable Base: GX24Q-4, Color Temp: 3500K, Rated Life (hours): 26000hrs