2015 - 18 Mustang GT 5.0L long tube headers. Factory Connect. 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. That connects to your factory exhaust. 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.