Litetronics LED Retrofit kit is designed to take the guesswork and uncertainty out of fluorescent troffer retrofitting for lighting distributors and their customers alike. No need to worry about selecting the correct LED tube; internal vs. external LED drivers; whether to bypass or use existing ballasts, keep or replace tombstones, etc. Litetronics® LED Retrofit Kit is an entirely self-contained one-piece unit, suited for 120v through 277v systems. It installs very quickly, avoids all costs of removing and recycling perfectly good fluorescent-troffer housings. It is UL and DLC listed, available in 3,500K, 4,000K or 5,000K color temperatures.