Introducing the Rob Roberts Final Strut Invector 12 GA Choke an essential tool for any avid shotgun enthusiast. Specifically crafted for 12-gauge shotguns this choke features a constriction diameter of .660 offering optimal performance. Engineered with precision from 174 PH U.S. Stainless Steel it promises durability and reliability. Bismuth shot shells shine when combined with the RRaptor BIZ choke making this piece a formidable part of the RRaptor Series. Benefit from years of product development and cutting-edge technology with this impressive addition to your shooting gear. Please note the design accommodates only a single barrel installation.