Perfect for mild ingrown toenails. Podiatrists use black's files to help clear debris from the nail sulcus and to file the sharp edge of the nail so it is less likely to dig into the edge of the toe. A blacks file can be used to prevent ingrowns and are a useful tool to help pack the edge of the nail with cotton wool or simply to round the edge of any difficult nails so they dont dig in. Blacks file is a professional instrument traditionally used only by Podiatrist's. It is used to clear debris from the sides of the nail bed, and shape & debur the sides of the nail. Extreme care must be exercised when using this instrument, as incorrect use can result on injury and may lead to complications such as infection, trauma or ingrown toenails. Blacks files are not recommended for use on diabetic feet or other medical problems that may affect the health or healing rate in feet.