- acoustic guitars
- electric guitars
Fretlight guitars have LEDs built into the fingerboard to help to train your fingers when learning the guitar. The concept was invented by J. Rusty Schaffer in 1987 and originally marketed as Smart Light. The Smart Light brand was discontinued by 2003, but Optek continue to distribute Fret Light acoustic and electric guitars (circa 2018).
Source: Optek website (archived 2002)