SPELAB Exhaust Header for 2004, 2005, 2006, 2007, 2008, 2009, 2010 Chevrolet Chevy Cobalt/Hhr/Saturn Replacing or upgrading your exhaust header is necessary for both engine performance and sound. Whether on or off the track, exhaust headers provide more horsepower and improved exhaust sound. SPELAB offers many products to help you create your own custom engine headers. It’s really easy and convenient to use: direct bolt-on, no modification needed.?The 4-1 off-road racing headers are designed to allow the exhaust gasses to flow more freely from each cylinder and combine in a more efficient manner.Tubing has been optimized for the 2.2L/2.4L engines. Fitment: 2005-2010 Chevrolet Coblat2006-2010 Chevrolet HHR2004-2005 Saturn Ion-12004-2007 Saturn Ion-22.2L/ 2.4L I4 Non-Turbo/ Non-Turbocharged Models ONLY; except Cobalt 2.0L Supercharged ModelsDoes NOT Fit Vehicles with EGR Port on Stock Manifolds Specifications: Brand Name: SPELABModel: EH28053Certificate: ISO9001:2000Application: Automobile Exhaust HeaderMaterial: Stainless SteelSurface: Mirror PolishInlet/ Outlet: 1.625″ X 0.875″ (Oval)/ 3.250″ Exhaust Header VS Manifold, which is the better choice? The structural differences between exhaust headers and manifolds are the material and size. From the material, exhaust headers are made of lighter, thinner steel, while exhaust manifolds are made of thick iron. Exhaust headers are also longer than exhaust manifolds. When in use, exhaust manifolds create back pressure, which lowers performance. Because each cylinder of the engine is given its own tube, however, headers eliminate this problem; thus, allowing the gases to exit without the creation of back pressure. Therefore, exhaust headers are a BETTER choice than an exhaust manifold.