Plug-and-play/ direct fit linear LED (UL type A) A plug-and-play, or direct fit, linear LED is probably what you're imagining –– a simple, one-for-one swap out of the original linear fluorescent lamp. This lamp works directly with the existing fluorescent ballast, so there is no rewiring nor ballast change required.

Ballast-bypass/ line voltage/ direct wire linear LED (UL type B) Bypass the ballast linear LEDs –– also known as line voltage or direct-wire linear LEDs –– work straight off the line voltage flowing directly to the sockets, requiring you to remove the original fluorescent ballast.

Hybrid/ dual technology linear LED (UL type A & B) Hybrid linear LED lamps are able to work both as a plug and play –– with the existing ballast –– and, once the ballast peters out, you can remove it and have the lamp run off of line voltage.