[Multiple Specifications] You will get 20 pieces 8 inch length stainless steel wire brushes. The diameters are 8mm, 10mm, 11mm, 12mm, 13mm, 15mm, 16mm, 17mm, 18mm and 19mm. Each brush has 1/4 inch hex shank to mount on any electric drill or die grinder (not included) [Professional Design] The wire cleaning brush is practical and designed for easy access into confined areas and narrow holes, which can be applied for tubes, ports, bearings, cylinders or other narrow areas that need cleaning. [Portable and Easy to Use] The 1/4 inch hex shank of wire bore brushes is significantly easier to use than screw shanks. You can mount the brushes on an electric drill or grinder, or on a matching driver handle for more efficient cleaning. [Wide Application] You can keep wire bore brushes in your car, garage, kitchen and office. [Wire Brush Tips] Please note that wire bore brushes are only for push-pull operation. Do not rotate counterclockwise or exceed 600 /min when using the electric drill or