This Cleaning Brush has stiff nylon long lasting durable bristles. One side is wider and long, the other side is narrow. There are 2 brushes in a package. Use with the Iosso Triple Action Oil to remove carbon burn and powder fouling. Use with the Iosso Bore Cleaner a little more aggresive cleaning. For industrial applications use the Safe-T-Solve, Metal Polish, or Mold Polish.