Kluson Guitar Tuning Machines - 3x3 - Nickel - Kluson WD90NPM/SL Real, authentic Klusons. Not Copies! Stamped onto the metal case in a single line down the center For slotted headstock Overall length: 4-1/4" (Breast Plate); Post To Post: 2-3/4" Center to center distance between posts: 1-3/8"; Post Length: 1-1/16"; Post diameter: 6mm Part Number: WD90NPM/SL