Buy your Browning Invector Choke Tubes from BattleHawk Armory today! The next generation choke tube. These choke tubes fit flush with the end of the barrel but are longer than competitors' tubes. Proprietary differential banded gas seal eliminates residue build up and makes chokes easy to remove and install. Integrated spring suspension holds the seal tight, yet allows expansion against the barrel wall for a perfect fit and a smooth transition for the shot column entering the choke Gas is controlled at the interface between choke and where it seats in the bore From skeet to full choke, patterns tighten consistently and reliably Invector-DS tubes fit only Browning shotguns designed for Invector-DS and are not for use in shotguns showing Invector-Plus or Standard Invector on the barrel(s).