These premium bore brushes are constructed with a cobalt blue fiber, ensuring they are easily distinguishable from other types of brushes. This thicker, more rigid fiber grade permits back-and-forth motion, unlike traditional brass and bronze brushes. They have a lifespan approximately 8 to 10 times longer than other brushes. The brush is wound more tightly and contains more fibers per inches than any other brush. For optimal results, use with Iosso bore cleaner and triple action solution to effectively remove all fouling, including copper, lead, plastic wad and carbon residue. This significantly reduces cleaning time and results in an exceptionally clean bore. These brushes are available in sizes suitable for rifles, pistols, shotguns and black powder firearms. The blue brushes are a trademark of IOSSO Products.