About the product: 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. flat file, works on fret edge and fret end round.You will experience the amazing efficiency of diamond. 3. The hand shank is made of solid wood: excellent grip and smooth operation. 4. Diamond abrasive way to coarse for this application, use fret erasers makes the frets as smooth as buttery. 5. It is made of high quality carbon steel& firmly coated with diamond-like grits. That ensure the long life service of this file. Specifications: Material: carbon steel+diamond grits+wood handle Products Size:227*20*20mm/8.9*0.79*0.79in Net Weight:163g/0.36lb Package Included: 1 x Fret File 2 x Neck Protection Sheet Made of high quality material,durable and practical to use. Perfect price-performance ratio, save you more money. The products is manufactured after strict screening, which is trustworthy. We will ship it ASAP,when you place the order. If you have any questions,please feel free to contact us, we will solve it for you immediately.