The KleenBore Double End Nylon and Bronze Cleaning Brush Combo Set has firm bristles to safely clean hard-to-reach areas in vent ribs, trigger assemblies and receivers. For added utility, it is double ended with larger bristles on one end and smaller, stiffer bristles on the other. The white nylon bristles are rugged and solvent resistant. The bronze bristle brush is great for removing stubborn fouling. FeaturesDouble ended with larger bristles on one end and smaller, stiffer bristles on the otherFirm Nylon & Bronze BristlesSolvent ResistantGreat for removing stubborn fouling