This axle-back exhaust system is constructed of 3" - 2-1/2" mandrel-bent brushed finished 304 stainless steel tubing for maximum strength and durability.This system features high-flow 304 stainless steel polished mufflers, producing a powerful sound. The mufflers has a polished finish for ultimate corrosion resistance. Finishing off this exhaust system are quad 3-1/2" diameter carbon fiber 304 stainless steel clamp-on exhaust tips. The tips features an aFe POWER logo for a unique style. This system produces a powerful sound unleashing all available horsepower and torque. Utilizing factory style hangers this system is a direct bolt-on system, which requires no cutting or modifications for a hassle-free installation. A mitered merge x-pipe is used to balance and evenly distribute exhaust pulses traveling through the exhaust system, minimizing exhaust drone and maximizing scavenging. This axle-back exhaust system incorporates factory style exhaust valve which use the factory exhaust valve motors (not included). The valve help regulate, direct and control the flow of exhaust gases by opening, closing, or partially obstructing passageways depending on throttle position for maximum performance. A mitered merge collector is used to decrease turbulence and increase exhaust velocity resulting in increased horsepower, torque and improved throttle response. Utilizing state-of-the-art computer-aided design technology, this exhaust system is designed for custom, high tolerance factory fitment. 100% TIG-Welded for race-proven strength and durability. MACH Force-Xp 3 IN to 2-1/2 IN Stainless Steel Cat-Back Exhaust System Carbon Audi RS5 18-20 V6-2.9L (t) Audi RS5 18-20 V6-2.9L (t)