The Rob Roberts Final Strut Invector 10 Gauge Choke is expertly crafted for optimal performance with bismuth shot shells. With a constriction diameter of .690 it is a valuable component in the RRaptor Series designed to enhance shooting accuracy. Constructed from high-grade 174 PH U.S. Stainless Steel this choke reflects years of dedicated research and technological innovation. Its unique design ensures superior shot patterns and is tailored for single-barrel shotguns. Ideal for those seeking precision and reliability this choke is a solid choice for enhancing your shooting experience.