Breakthrough Clean Technologies, Battle Rope 2.0, Bore Cleaner, .17cal/4.5mm California Prop 65 WARNING. These products contain a chemical known to the state of California to cause cancer, birth defects and other reproductive harm. Lead: Cas-No. 7439-92-1 .17 Battle Rope / 4.5mm Battle Rope Integrated bronze brush and detachable hard bristle nylon Threaded brass link allows for quick detachment of the hard bristle nylon brush Patented flex cable section allowing you to pass the rope through the ejection port without having to field strip your firearm Product Description The new Breakthrough Clean Battle Ropes are available in a wide variety of caliber widths, to cover all of your firearm cleaning needs. Designed to better clean the bore of your firearm, the Battle Rope's integrated bronze brush and detachable hard bristle nylon brush provide twice the cleaning action.