Casting Flanges beta 6/4 Titanium Alloy, Awesome strength, High durability. Bended forming, Piping Inside and outside smooth with Good exhaust efficiency, reducing welding failure issues. Use Japan Nippon steel & Sumitomo metal high quality pure G5 Titanium raw materials, heat resistant titanium alloy, same material as 2017 Nissan GTR factory titanium exhaust!