Grover Sta-Tite 18:1 ratio 3+3 tuning keys in nickel finish with ebony wood buttons. The classic open brass gear and fine 18:1 ratio makes this a favorite for both acoustic and retro electric guitars. Includes press-in bushings and mounting screws. Requires 11/32"(8.75mm) peghead holes. Mounting holes on each tuner are spaced 1"(25.4mm) apart. Features Grover's lifetime guarantee.