Ratio Tuned Machine HeadsRatio Tuned Machine Heads are the first and only machine head to incorporate the different string gauges into the tuning equation.The PRN-2311-B0 is a set of Ratio Tuned Machine Heads for an electric guitar that uses three a side tuners. It has a contemporary shaped button, has a two pin casing and is finished in Black. The InvisoMatch Mounting Plates (sold separately) make for easy installation on most headstocks.Features3 x 3 Contemporary Ratio TunersColor: Black, Material: SteelPost Dimensions: 6 x 27.7mm2 Pin Mounting Spacing: 9.9mmBushing Dimensions: 12.8 x 7.8mmHousing Dimensions: 18.5 x 15 x 9.2 mmInvisoMatch Plates are sold separatelyPart Number: PRN-2311-B0