The Agency Power Quad Titanium Tip catback exhaust for the Subaru STI is an awesome exhaust system that adds a mean growl and 20hp! Agency Power has constructed this system out of high quality T304 stainless steel 3 inch diameter piping. The piping is TIG welded with 1/2 inch flanges to ensure durability and hand polished. The catback exhaust features a resonator to eliminate droning. There is one high flowing canister to give this catback a great agressive sound and finishes at the bumper with quad titanium tips. The Agency Power catback exhaust will add style and performance to your 08-up STI.