Carlson's Cremator Choke Tubes feature our new Triple Shot Technology 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 allow a more gradual transition from the shotgun bore to the final constriction. The Cremator offers reduced pellet deformation, less flyers, more dense patterns, wrench-less installation, quick removal and muzzle protection. Made in the USA. *NOTE- Optima HP and Remington Pro Bore Long Range cannot be used with any steel shot larger than #2.Specifications and Features: Carlson's 11517 12 gauge 17-4 stainless steel Long range constriction Extended and ported Reduced pellet deformation No wrench needed for installation and removal Matte black