Use this MagnaFlow exhaust system when you're planning a grand tour or a weekend cruise in your 2012 - 2015 Audi A6 or A7 with a 3.0L V6 engine. It's for Audi owners who want to enhance their driving experience with a powerful exhaust note and better performance. The main piping is 2.5 inches, and it has 4 - inch polished tips. It's made of durable stainless steel, ensuring it can last through many miles of driving.