Graph Tech PRN-2311-C0, Machine Heads for Electric Guitar, 6 Pieces for 3 + 3 arrangement, Incorporate string gauges in tuning equation, half turn equals half tone on each string, Quicker and more accurate tuning of each string, Contemporary tuning buttons, Closed construction, 2-Pin mounting, Mounting hole diameter: 9.7 mm, Axis diameter: 6 mm, Ratio E - 12:1, B - 20:1, G - 35:1, D - 20:1, A - 24:1, E - 39:1, Finish: Chrome, Incl. InvisoMatch standard mounting plates for the use of existing screw holes