Feit Electrics 18 W ballast by-pass (Type B) non-dimmable linear LED tubes replace T8 or T12 fluorescent and LED tubes. They require direct wiring by by-passing the existing ballast. This added installation step enables efficient operation and less maintenance over time. Each linear LED light produces 1800 Lumens, emitting the same light output level as traditional fluorescent linear lights, while using less energy.