Avian X Waterfowl Crusher 12 Gauge Mobile Waterfowl Choke Tube - Bag more birds! The Avian X Crusher Choke Tube adds dense, even, and higher-powered shot patterns to your waterfowl hunting arsenal. Its unique design elements include wide groove technology, which keeps the shot pellets from the wad. Straight rifling keeps the wad from spinning, which helps preserve pellet accuracy. At the end, its unique porting and castle cuts on the crown provide exhaust channels, which direct gasses away from the shot string. The Crusher Choke Tube from Avian X is made of high-strength tempered steel for years of outstanding performance. Its black, high-performance, PVD finish ensures smoother shots and quicker cleanings. The polished end face enhances the sealing and seating inside the barrel. Rated for steel, tungsten, bismuth, and lead shot. Features: Creates dense, even, and higher-powered shot patterns! Wide groove technology keeps shot from the wad Straight rifling keeps wad from spinning Porting and castle cuts direct gas away from shot string PVD finish ensures smoother shots