This set of 3 x 3 Gotoh SE780 tuners are a classy traditional design for use on both electric and acoustic guitars. The press fit bushing fits a 11/32" hole (just smaller than 8.8mm) in the headstock to secure the string post. The 'Rock-Solid' string post improves the tuning stability of the tuner and stays strong during bending, special elastic parts eliminate any rattle in the post and transmission of string vibration to the instrument is maximised.