Carlson's Choke Tubes Winchester 12 Gauge Extend Turkey Choke 0.64 90129. 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" parallel section to produce the optimum pattern with your shotgun. Note: Not for use with steel shot. - Caliber: Winchester 12 Gauge - Constriction: Turkey - Diameter: .670 Specifications for Carlson's Choke Tubes Winchester 12 Gauge Extend Turkey Choke: Manufacturer: Carlson's Choke Tubes Color: Black Fabric/Material: 17-4 Stainless Steel Gauge: 12 Choke Tube System: Mossberg Accu-Choke Winchester Choke Browning Invector (Standard) Choke Type: Turkey Gun Make: Winchester Mossberg Browning Quantity: 1 Additional Features: Non-Ported Features of Carlson's Choke Tubes Winchester 12 Gauge Extend Turkey Choke Winchester 12ga Extended Turkey .670 Package Contents: Carlson's Choke Tubes Winchester 12 Gauge Extend Turkey Choke Carlson's Choke Tubes 90129: Winchester 12 Gauge Extend Turkey Choke 0.64