Hastings barrels have one of two choke systems. These Hastings II chokes are just over 2" long whereas the other Hastings choke system is 1.6" and is called a Tru Choke system. Manufactured from 17-4 stainless steel and hardened. For use with lead shot in all constrictions. Steel shot larger than #BB should not be used in any choke tighter than modified, BB and smaller size steel shot may be used through full choke constriction.