The 4G63 Expreme manifold is one of a kind in design. Starting off with its smooth curves, the Expreme exhaust manifold has excellent flow characteristics. The tubing used has a diameter of 45mm and is considered to be the best size when achieving for maximum torque. The material used for the piping and flange is aircraft quality SUS304 stainless steel. This material is very durable against corrosion and other harmful elements. Though in time, a light discoloration may be present, it is to be noted that this material will not deteriorate. The process used to assemble this manifold together is know as the lost wax method and is very advanced in the sense that it helps promote the strength and long lasting structural integrity. Along side this well developed manifold is a manifold accessory known as a heat shield. This one off in design heat shielding device is also made from durable SUS304 stainless steel. When attached, to the exhaust manifold, this Expreme heat shield will help promote cooler under hood temperatures, thus other peripheral engine devises will have cooler and longer lasting run times.