The B.O.N.E. Tool was designed specifically to clean carbon and fouling from the bolt carrier assembly area of MSR/AR style rifles. This quick-clean tool scrapes fouling from the bolt, bolt carrier and firing pin. Also includes an 8-32 threaded hole to act as T-handle. Available for 5.56mm or 7.62mm MSR/AR style rifles. Designed specifically to clean carbon & fouling from the bolt carrier assembly area of MSR/AR style rifles Scrapes carbon and fouling from the bolt, bolt carrier and firing pin Includes a 8-32 threaded hole to act as a T-handle Available for 5.56mm or 7.62mm rifle Note: While this tool fits many bolts flawlessly, it may fit some bolts better than others due to variance in bolts by different manufacturers.