Audi B9 S4 S5 3.0T 3" ARM Motorsports MidpipesThe ARM B9 Midpipes utilize an industry leading 3" design throughout 93% of the midpipe section, compared to the standard 2. 3" (60mm) size used by most other aftermarket options. The ARM B9 3. 0T 3" Midpipes will unlock a more exciting and aggressive exhaust note on your 3. 0T powered B9, with a fully reversible bolt on solution, no cutting or modification required! By removing the OEM front resonators which mute your Audi's 3. 0T engine, the ARM B9