TR EVO 4-9 Stainless Steel Exhaust Manifold with EGR is the ultimate exhaust manifold ever manufactured based on numerous hours of testing by tuners and customers satisfaction. The manifold is manufactured from 2mm thick, 45mm diameter of 304 stainless steel pipes, with 15mm thick flange on engine side and 12mm thick on turbo side. It is machine welded with no joint pipes and lost-wax finished flange.