Carlson's Cremator Non-Ported Choke Tubes -These chokes feature our brand new Triple Shot Technology. 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 series conveys a host of benefits to the shooter, like reduced pellet deformation, less flyers, and denser patterns. These choke tubes are non-ported.Combine the spectacular performance of today's premium ammunition with this breakthrough in choke tube technology and you'll see why Carlson's new CREMATOR series of choke tubes is setting the shooting world on FIRE. These chokes feature our brand new Triple Shot TechnologyThese choke tubes are non-ported.