Beretta Optima-Choke Tubes stand up to the heat of competition. Manufactured from high strength steel and finished in a nickel-alloy coating, these chokes guarantee significant corrosion resistance and have the ability to withstand the rigors of steel shot. Optima-Choke tubes are fully interchangeable on all Beretta barrels that are threaded for Optima-Choke. The various version are full interchangeable on 12 gauge guns with Optima-Bore barrels. These choke tubes are for 12 gauge shotguns with the Optima-Choke system.