2015 - 18 Mustang GT 5.0L long tube headers. Performance Connect, Unholy Union. All tubes are CNC mandrel bent for optimal flow. Made from 304 stainless steel for maximum corrosion resistance. Starting with a CNC cut 38 thick flanges into 2 diameter primaries, 3 slip - fit collectors with merge spike, then fitting into 3 high - flow cats. Extended leads are built to fit MBRP and Corsa as well as Stainless Works catback systems. The ultimate freedom in aftermarket connections. Headers are fully TIG welded and back purged. Mill finish, These, are TIG welded for strength and durability. These kits come with a lifetime warranty and proudly made in the USA.