A Black's file is a professional instrument traditionally used only by Podiatrist's. It is used to clear debris from the sides of the nail, 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 or ingrown toenails. That being said, it is preferrable that those choosing to cut their own toenails have appropriate tools, and know how to use them. Please see the instructional video below and consult your own Podiatrist for advice. Black's files are not recommended for use on diabetic feet, except when used by your Podiatrist.