Mercer Abrasives 181010B-20 Knot End Brushes For Drills and Die Grinders 3/4-Inch by 1/4-Inch Shank, 20-Pack Knot end brushes for drills and die grinders 3/4-Inch by 1/4-Inch shank Wire Type: 0.020 Carbon Steel 20-Pack Wire brushes available in all different styles and sizes