Nickel 3 per side 3x3 on a Plate vintage guitar locking tuning keys tuners. 15:1 Tuning Ratio. Please check the parameter drawing in the attached pics before placing your order. These are aftermarket tuners, not direct replacements for Kluson Tuners, and the size is different with original Kluson tuners. Post diameter: 6mm (String through Post); Bushing diameter: 9mm. Plate overall length: 102mm; Center to center distance between posts: 35mm. Distance between mounting screw holes: 31mm x 35mm x 27mm; Please contact us if you have any problem with the tuners.