Feit electric, 2 pack, 4′, 18w, led linear tube led light bulb, 4000 kelvin, direct replacement for fluorescent 4′ t8 lamps, no rewiring required, operates on existing electronic ballast, instant full brightness, including sub zero temperatures, contains no glass or mercury, no flicker or strobing, non-dimmable, 35,000 hours, 1600 lumens.