Guitar Fret Crowning Dressing File with 2 Edges Guitar Repair & Luthier Tools, Guitar AccessoriesThe four indicator socket is found in 1mm,2mm,3mm,4mm. 1mm works for extremely narrow frets, likes ukulele; 2mm works for all standard guitars, bass guitar, banjo, mandolin, guitar cigar box; 3mm, 4mm socket works on jumbo sills. This means that it will work on most stringed instruments. One flat file, works on the edge of the threshold and the round end of the threshold. You will experience the amazing performance of the diamond. Compatible With-Not only suitable for crowning guitar fret, but also for electric guitar, acoustic guitar, bass, Ukulele, etc.; A nice simple way to crown the frets if worn. Diamond abrasive to coarse for this application, use rubber fret makes the frets smooth as buttery. It is made of high-quality carbon steel and heavily coated with diamond grits. Which ensure the long life of this file. Color: As Shown Material: Carbon Steel + Diamond + Wood Package Content: 1 * Threshold is your file2 * Threshold Protection SheetOnly the above package content, other products are not included. Note: Light shooting and different displays may cause the color of the item in the picture a little different from the real thing. The measurement error is +/- 1-3cm.