Briley Beretta HP Helix 12 Gauge Choke .010 Caliber Improved Cylinder Black Oxide. The HEIX design provides faster/denser patterns and denser pellets with less wind blow-back. The longer parallel section (when used with the correct powder) of the Helix (when used with steel shot) provides additional momentum thus driving more pellets into the main wound channel where they belong. This choke benefits from a longer parallel section therefore driving more pellets into the main wound channel rather than the shorter more common straight-through configuration. The longer choke (when used with steel shot) will also provide more stable performance increased velocity and less pellet deformation; as well as a longer effective shooting distance. The longer parallel section allows for a longer choke therefore a longer effective shooting distance. Specifications for Briley Beretta HP Helix 12 Gauge Choke Tube: Manufacturer: Briley Gauge: 12 Choke Tube System: Beretta Optima HP Gun Make: Beretta Gun Model: Beretta HP Package Contents: Briley Beretta HP Helix Choke Tube Briley BHPHB12IC: Beretta HP Helix 12 Gauge Choke .010 Caliber Improved Cylinder Black Oxide