The Trim Doctor II Shotshell tool with ExactaTrim bushing by makes old shells like new! Worn-out crimps are trimmed off leaving a like-new crimp edge. 3-1/2" shells can be turned into 3" shells and 3" shells can be turned into 2-3/4" shells. Shells are held in perfect alignment producing sharp edges. Blades can be replaced by using standard heavy-duty utility knife blades. The Trim Doctor II can also be used as a shell disassembly tool by just removing the threaded guide rod. Just insert a shell into the opening and turn it while gently pressing on the blade guide. The top of the shell will cut off cleanly after a few turns.