Roush 421145 2011-2014 Mustang V6 Exhaust Kit with Round Tips ROUSH 2011-2014 V6 Mustang Exhaust Kit with round flash-chromed tips Enhanced aggressive sound tone and volume; Unique open-chambered design Increased air flow (decreased back pressure) for maximized horsepower and torque 409 stainless steel mufflers and pipes; Chrome-flashed 304 stainless steel tips Does not negatively affect emissions