EXCEPT Models With Sport Adaptive Air Suspension. '21-'25 Includes Sportback). This 2.5" diameter BORLA® Cat-Back™ system for the 3.0L SQ5 contains BORLA®'S patented SwitchFire® technology which truly blends the combustion pulses from both sides of the engine for improved performance and a custom sound. It delivers the classic S-Type sound with no drone inside the vehicle. The system also contains an Active Exhaust Valve that allows your vehicle to retain the factory designed valve operation. Includes Wiring Harness Extender for Active Exhaust Valve Actuator. The exhaust exits thru single 2.5" brushed T-304 stainless steel turn down tips on each tail pipe. Reuse 'factory 'False Tips' or add optional BORLA® tip kits (EXCEPT Sportback). The BORLA® tip kits feature dual 2.5" round outlets on each side and are available with bright chrome on T-304 stainlesss steel, black chrome on T-304 stainless steel, and brushed T-304 stainless steel finishes. Installation of optional dual tip assembiles REQUIRES removal of factory 'false tips' and cutting the valance. BORLA® Cat-Back™ & Axle-Back exhaust systems feature patented straight-through and multi-core technology to unleash hidden horsepower. Increased exhaust velocity adds power, driving excitement, fuel economy, and the distinctive BORLA® Sound of Power respected by motoring enthusiasts everywhere. Each system is built from premium T-304 austenitic stainless steel, superior to T-400 series knockoffs (such as 409), to give you the absolute best in performance and durability. Ultra-smooth mandrel bends ensure maximum flow & power, and precision computer numerical control (CNC) manufacturing ensures an accurate fit. Best of all, BORLA® stands behind every system with a Million-Mile Warranty. Just what you‘d expect from the world‘s most experienced (and most winning) exhaust brand.