Gotoh Grover-Type 3-Per Side Machine Head Set Keystone Chrome Grover style machine heads with threaded bushings for 10mm (13/32") diameter peg holes. Superior professional grade quality and precision made for those who demand nothing but the best for their guitars without breaking the bank. Featuring an 18:1 Gear Ratio and Gotoh's "Rock-Solid" technology so you dont have to worry about a post being misangled causing unproper tension on the strings.