Grover 502G Locking Machine Heads 3 Per Side Color: Gold; Gear ratio = 18:1 Includes all mounting hardware 3 Treble and 3 Bass, Set of 6 NEW Rotomatic design with "thumb screw" mechanism Peghole Requirement = 25/64 in. (10mm); Post Length = 1 in. (25.4mm); Post Diameter = 15/64 in. (6mm); Bushing Type = Hex Head screw in; Collar Diameter = 25/64 in. (10mm); Collar Height = 25/64 in. (10mm); Mounting Screw Hole Location = 6 O'clock low