Carlson's Turkey Choke 12 Gauge Mossberg 500 Extended Turkey Choke Tube - Carlson's extended turkey choke tubes extend approximately 1 inches from the end of the barrel. They are manufactured from 17-4 heat treated stainless steel and have a matte blue finish. Carlson's extended turkey choke tubes feature a 1.05 inches parallel section to produce the optimum pattern with your shotgun. Features Extend approximately 1 inches from the end of the barrel; Manufactured from 17-4 heat treated stainless steel; Matte blue finish; 1.05 inches parallel section;