Carlsojn's uses 17-4 PH stainless steel to make their products, which is one of the finest corrosion resistant materials available. Because Carlson's uses higher quality materials, their Flush Mount choke tubes stand up to lead free loads and heavy buffered shotshells, while out performing other competitive choke tube brands. Carlson's Choke Tubes are an excellent option to optimize shot patterns from your Beretta/Benelli Mobil shotgun to your sporting or hunting needs.