you get 30 wire bore brushes for drill , each for 10 pcs, all of them have 1/4 inch hex shank, enough for your need in common wire brush applications cleaning brush for drill offers easy access into narrow holes and confined areas, designed for use on right angle grinders; Industrial wire brushes are suitable for cleaning steel parts, machinery, the unfinished metal parts, paint stains, without damaging surfaces or fine features the drill wire brush is 1/4 inch hex shank fits for power drills, impact drivers, die grinders, the overall length is 4-3/4 inch, different width includes 8, 10, 11, 12, 13, 15, 16, 17, 18 and 19mm, so you can choose the right size to use according to your needs bore cleaning brushes are made of Metal, strong and sturdy, can clean rust and detail completely; Twisted wire is for increased cleaning action you can keep wire tube brushes in your car, garage, and kitchen, and the bore brushes are suitable for cleaning, polishing, painting, or rust removal in automotive, fabrication, machining and smiting applications, and a lot of others, Manufacturer: Giuneuow