Agency Power designed a freer flowing header for the FA20F powered 2015+ Subaru WRX. AP used 1.5" schedule 10, thick-wall stainless steel tubing, to maximize heat absorption, heat dissipation, and be strong enough to support the weight of the turbo. The new flanges are water-jet cut for precise fitment, ensuring leak free seals. For their FA20F equal length header Agency Power uses 3/8" thick flanges at the turbo side of the manifold and 1/4" thick flanges at both exhaust port banks. The Agency Power equal length 2015+ WRX header comes with a limited lifetime warranty when you fill out their warranty form here.