The AVO cat-back exhaust system for the WRX and STI is constructed from 3" stainless steel, and designed to bolt up to the stock locations/flanges on the Subaru WRX and STI. The high-flow design is rated of 86 dB, making it a good choice for noise concious performance-oriented customers. Comes with a 3 1/4" rolled tip.
Note: Are you using a stock j pipe or downpipe? If yes, the GrimmSpeed Subaru Stock DP to Aftermarket 3 in. Catback Adapter p/n 077046, is required.