BBK Performance short mid X pipes with catalytic converters are specifically designed to be used with BBK full Length exhaust headers to complete the exhaust installation to your cars cat back exhaust system. This BBK mid pipe is designed and built with 2-3/4" CNC mandrel bent tubing for maximum exhaust flow and high flow catalytic converters. All BBK mid pipes feature ball and socket style connectors for simple installation and adjustment for good ground clearance. The BBK merged X center section crossover is designed to maximize the exhaust flow potential of your Mustangs high performance engine to get the maximum horsepower and torque available to the ground. Every BBK mid X pipe offers performance, quality and value that guarantees years of top performance for your Mustang. Designed to Fit BBK Long Tubes part # 1641 and 16410