Hevi Shot Non-Ported Extended Range Waterfowl Choke Tubes for shooting going-away long-shot birds. Built to put maximum lethal pellets on your bird. This choke features a knurled fore end for easy installation in the field under any condition without tools. The non-ported version is designed to be used with ammunition that has rear breaking wads.. The tubes are formed from aircraft stainless steel for years of carefree use and finish in matte black for concealment.