Features 1、High processing quality and high finish, and can produce various high accuracy mold cavities. 2、The rotary burr is applied to heavy duty rotary lapper sleeve to power drills, air tools and die grinders. 3、Before using the product, you need to grind, polish, carve and polish wood surfaces. 4、Most commonly applicable to 1/4 inch shank, suitable for all electric and cordless drills. 5、Long service life, 10 times more high durability than high speed steel cutting tool and 200 times more high durability than small grinding wheel. Specification Item Type: Rotary Burr Material: Carbon Steel Color: Black Specification Shape: Ball, Oval, Cylinder, Large and Small Cone Stem Diameter: Approx. 6.1mm/0.24in Shank Diameter: 1/4 inch Package List 10 x Electric Black File Grinding Head