Tsudo Civic Si Coupe Sedan 06-11 K20 Racing Header FA5 FG2 Manifold Manufactured from T304 / SUS304 stainless steel for durability and high corrosion resistance CNC machine mandrel-bent stainless steel tubing for maximum exhaust flow Significant weight reduction compared to OEM exhaust system Improves horsepower, torque, throttle response, and fuel mileage Includes all necessary hardware (bolts and gaskets) for Bolt-on installation with typical hand tools