Carlsons flush mounted choke tubes are available for most shotgun models and serve as a perfect replacement to damaged, worn out or misplaced factory flush mounted choke tubes. Carlsons flush mounted choke tubes are manufactured from corrosion resistant 17-4 ph stainless steel, they are compatible with steel or lead shot (steel shot should not be used in any turkey choke tube). Specifications: - Fits: Winchester - Gauge: 20 - Type: Flush - Constriction: Cylinder - Diameter: . 620