The Invidia Mitsubishi EVO 3-inch Turbo outlet directly replaces stock restrictive turbo outlet, allowing the factory turbo to flow exhaust gasses much more efficiently, reducing lag and improving throttle response. It is designed to work with your factory exhaust as well as any exhaust that would keep the factory Turbo outlet and stock donut gasket. It is constructed of fully polished 304 stainless steel. Includes new solid copper exhaust gasket to ensure a proper seal.