DNA Motoring HDSME06L4 Stainless Steel Exhaust Header Manifold Made of High Quality T-304 Stainless Steel with Computerized Mandrel-Bends for Strength and Durability 4-1 High Performance JDM Racing Spec. Design, Produces the Most Top End Power Offers the Best Flow Characteristics for the Engine at High Engine Speeds Piping Diameters: 4 x 1.625" Manifold Piping; into 1 x 2.25" Major Pipe Application: 06-12 Mitsubishi Eclipse 4-Cylinder (Instruction NOT Included, Professional Installer is Highly Recommended)