Carlson's Ported Turkey Choke Tube Fits Mossberg 835 or 935, 12 Gauge .675 Constriction Designed for the serious turkey hunter, each Super Full Choke has been specifically bored to throw the optimum pattern at short and long distances. Each choke is ported allowing gases to escape quickly reducing recoil and muzzle jump in the process. Each Choke Tube is manufactured from aircraft stainless steel and a blue non-reflective finish has been added. Lifetime warranty Not for use with steel shot.