The Roush Performance Axle Back Exhaust is the perfect upgrade for your Mustang. This is the most aggressive, highest flowing, and loudest exhaust system that Roush offers. Sound levels at high RPMs may exceed local noise ordinances. Roush Exhausts are made from stainless steel and are finished with a chrome flashing process. This exhaust does not come with exhaust tips. Roush Exhausts are completely bolt on and can be installed with minimal effort. All necessary hardware and instructions are included. The part number for this item is Roush 401339 and it fits 2005-2009 Ford Mustang GT (4.6 V8 Models w/ Roush Rear Valance) models. Your Mustang MUST have the Roush Rear Valance or this exhaust will not fit.