DNA Motoring HDS-MM9718L Stainless Steel Exhaust Header Manifold Precision machined Steel flanges that provide a tight seal at the head and allows a high flow rate through the primary tubes Made from high quality T304 Stainless Steel for strength & durability Constructed with TIG welded CNC machine flange for precision & fitment All tubing is mandrel-bent Comes with O2 sensor bung insertion & metal gasket