These brand new beautiful Tyler Mountain nickel planetary geared machines with pearlized plastic buttons will look great on your instrument. These are quality, well made machines at a very affordable price. * The shaft size of these are 9.5mm and include all the hardware you will need for installation. This is for (1) one set of 5 nickel machines. * 3/8" shaft size * Fits 1/2" to 5/8" pegheads