The Rob Roberts Final Strut ProBore 12 Gauge Choke is expertly crafted for precision and performance. Engineered from robust 174 PH U.S. Stainless Steel this choke is part of the innovative RRaptor Series developed through years of dedicated research and advanced technology. With a constriction diameter of .655 it is perfectly optimized for pairing with bismuth shot shells delivering superior results. Note that the design allows for placement in only one barrel of your shotgun ensuring focused and effective performance. Ideal for enhancing your hunting experience this choke offers durability and reliability in every shot.