Cleaning jags have machined aluminum components that don’t react with ammonia-based solvents like brass parts sometimes do. Won’t produce blue-green stains on your patches that can be misinterpreted as “false positive” indications of copper fouling, so you’ll know when your bore really is copper-free. Similar in hardness to brass, Copper Eliminator parts won’t scratch the bore or damage the muzzle, and they’ll stand up to hard use. Pure aluminum jags are specifically designed for use on Copper Eliminator rods to maintain the full integrity of the CE system. They can also be used on other rods with the same female thread patterns.