Carlsons 67001, Extended Turkey Choke Tubes, 12 Gauge .675, Crio Plus Carlson's extended turkey choke tubes extend approximately 1 inch 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 1.050 inch Parallel section to produce the optimum pattern with your shotgun