The MagnaFlow 4 X 9in. Oval Straight-Through Performance Exhaust Muffler 11255 is engineered to enhance your ride with a healthy helping of our signature exhaust sound and dyno-proven performance thanks to its free-flowing straight-through perforated stainless steel core wrapped in stainless steel mesh and acoustic fiber fill. The reversible, universal 2.25/2.25in. diameter inlet/outlet Straight-Through layout allows you to install it in whatever orientation and configuration you see fit. However, professional installation is highly recommended. Muffler 11255s weight-optimized 4x9x18in. oval-shaped body features a satin finish that elevates the overall aesthetics of your current exhaust setup. 11255 is made of durable, corrosion resistant stainless steel and produced using cutting-edge CNC precision robotic manufacturing techniques, all backed by MagnaFlow's limited lifetime construction warranty.