1. Four gauges slot are provided in 1mm,2mm,3mm,4mm. The 1mm slot works for extra narrow frets, likes ukuleles; The 2mm slot works for all standard guitars, bass, banjo, mandolin, cigar box guitars; The 3mm,4mm slot works for jumbo frets. That means it'll work on most stringed instruments. 2. One flat file, works on fret edge and fret end round.You will experience the amazing efficiency of diamond. The hand shank is made of solid wood: excellent grip and smooth operation. 3. Diamond abrasive way to coarse for this application, use fret erasers makes the frets as smooth as buttery. 4. It is made of high quality carbon steel& firmly coated with diamond-like grits. That the service of this file. 5.High Wear-resistant and excellent durability Size:227 x 20 x 20mm Net Weight:163g/0.36lb Material:Carbon steel + diamond matte + wood colour:Wood color+silver Package Contents: 1 x Fret File 2 x Neck Protection Sheet 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.