Hosco double edged nut slotting files are massively popular the world over, this set is made up of gauges catered towards acoustic guitars (but can of course be used on any guitar) and is made up of the following widths: .016"/.042", .026"/.050" and .036"/.055", having specific file edge widths makes slotting nuts considerably quicker and easier. Slightly wider slots can be made by rocking the file from side to side when filing the slot.