Florescent tube replacing by LED tube, ballast compatible LED tube or ballast by-pass LED tube, how to install LED tube in practical.
4FT T8 LED Tube Light, 18W (40W Equivalent), 5000K Daylight White, Dua – YGS-Tech
Feit Electric 40-Watt 8 ft. T8/T12 FA8 Single Pin Type B Ballast Bypass Linear LED Tube Light Bulb, Daylight Deluxe 6500K (2-Pack) T96/865/B/LEDG2/2 - The Home Depot