IOSSO AR15/AR10 Upper Rec Brush w/ Handle 2PK These brushes are sized to tolerance for precision cleaning. The distinctive blue fiber holds its shape well and allows for back and forth action unlike traditional brushes. When used with the IOSSO Bore Cleaner, it will remove nasty carbon burn and all other fouling including copper and lead. Directions: Apply the IOSSO Bore Cleaner sparingly to a brush. Run it through the chamber 8 to 10 times then follow with clean dry patches until one remains clean. Repeat if necessary. Cleaning can be done in fifteen minutes or less with no smell, no running or splattering of fluids. Upon inspection, the bore will be free of all fouling.