The APR CB100016 RS6 Exhaust is a stainless steel, mandrel bent, cat-back exhaust. The APR exhaust begins after the factory catalytic converters with dual 2.5" pipes, and continues back to the innovative center muffler. From there, it splits to two separate mufflers placed in the factory location with a pair of twin 2.5" Tips that fit neatly in the factory RS6 valence openings. The APR CB100016 exhaust really helps to awaken the Audi 4.2T, but keeps the stateliness that it deserves. The APR RS6 exhaust is a very quiet system, and will not turn your prized vehicle into an off-road buggy. The system is hand-built with TIG welding, fully stainless construction, and CNC'ed hangers. You will not find a higher quality system on the market.