For use with an electric drill, router or die grinder tool with 1/4" shaft. Suitable for polishing, grinding, shaping and burnish wooden surfaces. Double diamond cut so a lot stronger than cheaper models. Tungsten carbide burr's not HSS like cheaper models. Extra long for access into restricted awkward areas. Total length of the burr 175mm. They all come with a 6mm / 1/4" shank. They will grind most steel types, glass, plastics, marble / granite and various other materials. SET Includes; Cone burr Cylindrical burr small Cylindrical burr medium Cylindrical burr large Rounded cylindrical burr. Flat tipped cylindrical burr small Flat tipped cylindrical burr large Comes in a box for easy storage and transportation. Professional quality carbide burr set for everyday or commercial use.