Grover 2+2 Mini series bass tuners in black chrome finish. The specially machined housing provides precise tolerances that prevent slippage and allow for fine tuning. The sealed gear box has permanent lubrication that makes them friction-free for life. 20:1 ratio. Requires 9/16"(14mm) peghead holes. Includes screw-in bushings and mounting screws. Features Grover's lifetime guarantee.