Aeroflow external wastegatemerge is designed to allow an external wastegate to be welded onto a turbo manifold collector or turbo manifold runner pipes. When this is done with just a single pipe it creates a weak point prone to cracking and/or breaking especially with extreme heat cycles. This unique curved design is intended to be strong which extends past the weld joint to allow for a strong and robust lap joint. This allows you to position the merge anywhere on the outside radius of the 90-Degree bend of a 2.5" OD piece of tubing. Made from cast 316 weldable stainless steel (compatible with 304 stainless). The wastegate flange side allows use of any brand wastegate by welding your flange of choice on, whether it be a 44mm,45mm,50mmor 60mm.