Piper stainless steel performance rear exhaust boxes are designed to fit to the standard factory OE exhaust system. All Piper rear boxes are manufactured from T304 high grade stainless steel and are covered with a lifetime warranty. The Piper performance back boxes are designed to be less restrictive and therefore release a moderate power gain of approx 5%. You will also benefit from a slightly deeper exhaust tone and there are numerous tailpipe designs to choose from. Awesome power, awesome noise, awesome looks!