Carlson?s Cremator Choke Tubes feature a brand new Triple Shot Technology (TST) and is offered in a variety of constrictions. TST is a series of three graduated rings in the taper section of the choke tube that allow more gradual transition from the shotgun bore to the final constriction. This design offers reduced pellet deformation, less flyers and more dense patterns. These benefits make the Cremator Series incredibly effective on all type of waterfowl. The Cremator series has no size or speed restrictions with steel shot in any of the three constrictions. You also get the benefits of an extended choke tube, including a 25% longer parallel section for tighter, denser patterns, wrench-less installation, quick removal and help with muzzle protection. This item is made in the USA, carries a lifetime warranty, and is precision machined from heat-treated 17-4 stainless steel.