The Iosso Eliminator Pistol Bore Brush features premium cobalt blue fiber construction designed specifically for .357 and 9mm pistol bores. This advanced cleaning brush delivers superior performance with thicker stiffer fibers that allow safe back-and-forth cleaning action.Iosso Eliminator Pistol Bore Brush for .357/9mm calibersCobalt blue fiber construction - trademarked Iosso designThicker stiffer grade fiber allows back-and-forth actionWound tighter with more fiber per inch than standard brushesReusable design - may be used several times before wearingCompatible with Iosso Bore Cleaner and Triple Action SolutionRemoves copper lead plastic wad and carbon burn foulingEngineered to drastically reduce cleaning time while delivering an unbelievably clean bore. The blue fiber trademark ensures you're using genuine Iosso quality for optimal pistol maintenance and accuracy.