If you own files, you really must have this inexpensive tool. It's a toothbrush for your files. When you file metal, especially leatherhard metal clay, you create filings that build up and clog a files teeth. If you don't clean the teeth they will eventually stop cutting and become ineffective. Leatherhard clay clogs the teeth very quickly. The teeth should be brushed everyday, but it must be metal. Toothbrushes do not work for this. To get the filings out you need this tool. It has steel bristles that brush the filings from the teeth, keeping your quality files in top cutting shape. Made in USA.