GE LED tubes replace 48-inch t8â1-inch diameterâfluorescent bulbs using the existing fixture and electronic ballast. Why make the switch to ledge LED tubes 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 fluorescent tube with nearly the same light output helping you save money on energy. And, they're mercury free. Use LED tubes to provide a clean natural lighting with high CRI and color-rendering.