For almost a century, Grover's been keeping the world's finest string instruments in tune. It started in the late 1800's when Grover first produced a few guitar and banjo machine heads, then expanded into the additional production of tuners for bass guitar, pedal steel, mandolin, dulcimer, ukulele, and violin. Designed to fit over a standard 6-string nut, the Grover Perfect Guitar Nut raises the strings to allow playing with a steel bar, Dobro-style.