CXRacing Stainless Steel Exhaust Manifold Turbo flange 38mm Wastegate M8 threaded CXRacing 304 Stainless Steel Exhaust Manifold Turbo flange 38mm Wastegate Flange is approximately clsoe to 1/2"" (12mm) thick Holes are threaded M8 x 1.25 This is perfect for a custom build header or turbo manifold.