The Tipton Universal Bore Guide protects the bore, chamber and action of your rifle by properly aligning the cleaning rod and reducing solvent overflow. Three interchangeable tips cover most centerfire calibers from 17 to 460.Note: The tips insert into the chamber and chamber dimensions do not directly correlate to bore diameter, select the tip that provides the best fit for any given cartridge.Small fits most cartridges .17-.24 (up to 6mm)Medium fits most cartridges .25-.30 (6.5mm- 7.62mm)Large fits most cartridges over .30 (over7.62mm)Compatible with cleaning rods up to .425" diameter. Adjustable position sliding collar for bolt actions works with most centerfire rifles. Fits bolt diameters .695" or larger. AR-15 collar fits securely inside receiver of AR-15 style rifles. Closed overall length of 31.5" long.