This BBK Performance short mid pipe is specifically designed to be used with BBK CNC series long tube exhaust headers for the 2015-2023 Mustang 5.0 GT to complete installation to your factory resonator box or resonator delete X pipe.These mid pipes are made from CNC mandrel bent 3.0 inch Tubing and feature high flow catalytic converters and a merged step down to allow installation to the factory exhaust system. Each BBK mid X pipe offers performance, quality and value that guarantees years of top performance for your Ford Mustang.Required for installation of BBK Long Tubes 4046, 40460Note: If using the Factory 2-3/4 in. Cat back exhaust system, a small reducer will be required to step down from the 3 in. BBK mid pipe to the 2-3/4 in. factory catback exhaust, or it can be simply welded.