Tig welded from WELD ELL 304L 8GA Stainless Steel. Head plate and turbo flange are CNC cut from 1/2" 1018 mild steel. Jig assembled and back purged welded. Designed with the T3 turbo flange. These turbo manifolds are designed for superior strength and performance. Comes 44mm wastegate flange standard. Option for T4 flange also availible.