Carlson&';s Cremator Choke Tubes feature Triple Shot Technology (TST) and is offered in close mid and long range constrictions. TST is a series of three graduated rings in the taper section of the choke tube that allows a 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 effective on all types of waterfowl throughout the entire season. The Cremator series has no size or speed restrictions with steel shot in any of the three constrictions. You also get all the benefits of an extended choke tube, including a 25% longer parallel section for tighter and more dense patterns, wrench-less installation, quick removal and helps with muzzle protection. They are offered in your choice of ported or non-ported configurations. Like all of our tubes Carlson&';s Cremator Series Choke Tubes are made in the U.S.A., carry a lifetime warranty and are precision-machined from heat-treated 17-4 stainless steel.