These are quality well made machines at a very affordable price.These brand new beautiful Tyler Mountain nickel planetary geared machines with pearlized plastic buttons will look great on your instrument. The shaft size of these are 9.5mm and include all the hardware you will need for installation. This is for one set of 4 nickel machines.FeaturesPlanetary Machine gear ratio: 4:13/8" shaft sizeFits 1/2" TO 5/8" inch pegheads