Hrph 6 PCS Guitar Setup Kit Nut files/String Spacing Ruler/Action Gauge Luthier Tools Three double-edge nut files, with 6 different specs,the set of tree files does the work of six,available for acoustic guitar. One stainless steel ruler,used at the bottom while nut slotting,act as the nut slotting depth benchmark,also to prevent scratches finish,It can quickly find the right space, act as nut positioning for classical,acoustic, electric and bass guitar A sheet of string action ruler,with centimeter and inches unit on side,can quickly finds the right distance,measuring the accurate string height. One special patent string winder,available for manual or fixed at electric tolls to operate Enclosed a collectable packet, convenient for package,prevent the loss of tools