These are designed to use on the lateral boarders of ingrown nails.  These burrs are very helpful with patients that will not allow you to use a nipper or splitter to remove nail.  There are two sizes.  The large is only about 1/16th inch in diameter, and the smaller one is about one third the size of the large one. Begin with the large burr as far proximal as possible - thin groove distally.  When you have reduced the lateral boarder as much as possible with the large burr, then follow in the same groove with the small burr, going as close to the nail plate as possible.  It will be very easy to remove the offending spicule after using these burrs.