Cleaning an AR-10/15 has never been an easy task. There are no brushes that fit correctly for complete cleaning. Wrapping a patch around a brush to make it fit and using tools to scrape away the fouling in not foolproof. The brushes are superior because they are sized to tolerance for precision cleaning. They are made out of a distinctive blue fiber that is very thick and stiff which holds its shape well and allows for back and forth action unlike traditional brass and bronze type brushes. They may be used several times before becoming worn. The brushes are wound tightly to allow for more cleaning area per inch. The shank is a solid construction sized to fit 8/32 cleaning rods. When used with the Iosso Bore cleaner and Iosso Gun Oil, it will remove nasty carbon burn and all other fouling, including copper and lead.