AVOTurboworld's Gen 3 Cat Back Exhaust System for the WRX EJ25 2006-2007, Forester XT EJ25 2004-2008 & STI EJ25 2006-2007 is constructed from 3" stainless steel, and designed to bolt up to the stock location flanges. The high-flow design is rated at around 89 dB, making it a good choice for noise concious performance-oriented customers. Comes with a 4" round-rolled adjustable exhaust tip. The AVO cat back has a tapered flange at the front so that it can fit a standard OEM front pipe with a donut gasket setup. This will ensure the flex in the system still operates as it was intended to from factory.