In addition to world-class ammunition, Hevi-Shot offers the best chokes for your hunt, with gun specific styles available for most gun models. The chokes are manufactured from aircraft-quality 17-4 stainless steel and utilize state of the art patterning equipment, to achieved the optimum constriction by gun type, for the best possible pattern. Each Hevi-Choke has a knurled fore-end and can be hand tightened for easy field change-outs. This 20 gauge Waterfowl choke tube is an extended-range and ported. It is compatible with Remington 870/1187 and Charles Daly Pump/Auto shotguns.