1. Available in 1mm,2mm,3mm,4mm slots. 1mm slot for extra narrow frets such as ukuleles; 2mm slot for all standard guitars, basses, banjos, mandolins, cigar box guitars; 3mm, 4mm slots for jumbo frets. This means it can be used on most stringed instruments. 2. A flat file for rounding the edge of the fingerboard and of the fingerboard. You will experience the amazing efficiency of the diamond. The handle is wrapped in a layer of rubber: excellent grip and operation. 3. The diamond abrasive way is too rough for this application, using a fingerboard eraser will make the fingerboard as as butter. 4. It is made of high quality metal and firmly coated with a diamond-like abrasive. This ensures a long service life for this file. 5. High abrasion resistance and excellent durability Colour:Photo Color Material:metal+rubber Size:19.5 x 1 x 1cm Package Contents: 1 x Fret File 2 x Neck Protection Sheet Only the above package content, other products are not included. Note: Light reflection 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.