Universal for stringed instruments, guitar, mandolin, bass, ukulele and banjo, etc. 13 round files of different dimensions to polish the grooves of the strings, and makes the groove of the strings very smooth. 1 flat file to polish the nut and the bridge. Made of high quality metal, compact and resistant. Small size, convenient to use and carry. Number of files: 13 round files and 1 flat file Item size: 7.7 * 3 * 1.5 cm / 3.0 * 1.2 * 0.6 inch Material: Metal Color: Blue Package Contents: 1 * Guitar Nut Bridge File Set Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.