Our Daylight T8 LED tubes replace 48-inch T8u1-inch diameterufluorescent bulbs using the existing fixture and electronic ballast. It's slim size fits in the same fixtures as traditional 48-inch T8 fluorescent bulbs. Why make the switch to LED? Our LED tubes are rated to last 36,000 hours. They provide long 16-year life based on six hours use per day, so you'll replace less often. They use less energy than a 32-Watt T8 with nearly the same light output helping you save money on energy. And, they're mercury free. Use Daylight T8 LED tubes in active spaces like playrooms and workout rooms to provide very cool, bluish-white light.