The Roush Performance Axle Back Exhaust is the perfect upgrade for your Mustang. Featuring an open-chambered designed muffler, this Roush Exhaust features an aggressive sound that is unique to Roush without the boom/drone found on many other aftermarket exhaust systems at cruising speeds. Roush Exhausts are made from stainless steel and are finished with a chrome flashing process. The exhaust tips are embossed with the Roush logo. Roush Exhausts are completely bolt on and can be installed with minimal effort. All necessary hardware and instructions are included. This exhaust system is "active ready" meaning you can use it with the Roush Active Exhaust Upgrade if desired. The part number for this item is Roush 421920 and it fits 2015-2016 Ford Mustang GT (5.0 V8 Models) with a Roush Rear Valance. If you have not upgraded to a Roush Rear Valance, this exhaust will not fit.