The CARLSONS Modified 12 Gauge Win-Choke choke tubes are made of 1704 stainless steel and are flush mount.
These choke tubes are compatible with shotguns using Win-Choke thread size and can handle magnum and steel shot loads.
Designed for 12 gauge, the Win-Choke-style tubes have a thread pattern of .812"-32 tpi and should not be used with more than 2¾" lead shot loads for the Thinwall models.