Vibrant Performance's Mitsubishi 4G63 Exhaust Manifold Flange will save you the time and high cost of getting header flanges cut when you need to fabricate a custom header or turbo manifold. This flange is cut from 3/8'' (10mm) thick Stainless Steel. The port sizing on these exhaust header flanges is optimized for use with standard 16 gauge (0.65" wall), OD tubing.