The COBB Cat-Back Exhaust for the EcoBoost F-150 is constructed of quality 304 stainless steel tubing. Mandrel bends ensure maximum flow throughout the entire system. An integrated flex section provides a small amount of compliance during installation and reduces stress on components once installed. The triple-chambered muffler with 3" inlet/outlets keeps the exhaust note crisp and prevents unwanted drone. The three sections are joined together using cast 3" 2-bolt flanges and multi-layer steel gaskets for a leak-free assembly. Connecting to the factory downpipe assembly is a breeze with an OEM style 2-bolt flange.