Regularly $2.97 - Double Cut 1/4 x 1/2 inch 14 degree Taper Carbide Burr with a 3mm shank. This burr does cut on the end. 3mm is slightly smaller than 1/8 inch. While they will tighten down enough with some tools using an 1/8 inch collet, a keyless chuck always works. For use with Dremel rotary tools.