The Rob Roberts Biz Raptor Optima HP 20 Gauge Choke is engineered for performance and reliability crafted from durable 17-4 PH stainless steel. This choke is specifically designed to enhance the effectiveness of bismuth shot shells making it a powerful addition to the RRaptor Series. Developed through years of innovation and advanced technology this choke provides precision and durability. Note that the RRaptor choke is designed for placement in a single barrel optimizing your shotgun's performance with unparalleled precision.