Briley Remington RemChoke Extended Choke 12 Gauge Improved Modified .025. The straightness of the tube does not change with the degree of concavity of the shot. The angle of constriction is the same as the AXIS therefore the tube is home to many choke constrictions. However do not let the concavity of the throat fool you; a very concave throat will give you a denser and more uniform pattern than a concave throat. A concave throat will give you a more uniform and closer pattern than a concave choke tube. A concave throat will give you a more open gap with greater velocity and energy transfer than a concave throat. Remember to let your gun breathe; carbon in all its forms tends to pull the shot out faster and causes recoil. Specifications for Briley Remington RemChoke Extended Choke Tube: Manufacturer: Briley Gauge: 12 Choke Tube System: Remington Choke Gun Make: Remington Package Contents: Briley Remington RemChoke Extended Choke Tube Briley REMX212IM: Remington RemChoke Extended Choke 12 Gauge Improved Modified .025