Carlson's Choke Tubes Stevens 555 Sporting Clay 12 Gauge Choke Tube Skeet Stainless NSN N. These choke tubes produce extra tight patterns with copper plated and buffered lead turkey shotshells. These chokes produce dense patterns and extend approximately 1" from the end of the barrel. These chokes have a matte blue finish and should not be used with steel shot. We have found the .665 Extended Turkey Choke Tube to produce the most consistent patterns with all turkey loads. Our Extended Turkey Choke Tubes have a 1.050" parallel section to produce the optimum pattern with your shotgun. No Steel Shot Larger than #4 may be used in our Turkey Choke Tubes Specifications for Carlson's Choke Tubes Stevens 555 Sporting Clay 12 Gauge Choke Tube: Manufacturer: Carlson's Choke Tubes Color: Stainless Fabric/Material: 17-4 Stainless Steel Gauge: 12 Choke Tube System: Stevens 555 Choke Gun Make: Stevens Quantity: 1 Additional Features: Non-Ported Included Accessories: Choke Wrench Country of Origin: USA Features of Carlson's Choke Tubes Stevens 555 12ga Sporting Clay Stevens 555 12ga Sporting Clay Cylinder Package Contents: Carlson's Choke Tubes Stevens 555 12ga Sporting Clay Carlsons Choke Tubes 15552 Stevens 555 12ga Sporting Clay Skeet Stainless NSN