Key benefits Improves exhaust gas emission performance, thereby helping to save fuel and increase engine power. Material: aluminum alloy for maximum durability and stability; durable, sturdy and longlasting use. Compatibility: A3, A4 B8 B6, A6 C6, A5 B7, Q5, C5 8P, Q7, TT C7 8V, A1, Q3 S3, A7 B9 8L. Turbo whistle effect: makes the vehicle sound like a turbo car. The larger opening should face the inside of the muffler. Orientation note: ensure the larger opening faces toward the inside of the muffler for results. Use scenarios Daily driving: provides a sportier exhaust note with minimal modification to your standard setup. Highway or spirited driving: delivers a turbolike sound that enhances the driving experience while maintaining efficiency. Car shows or demonstrations: showcases a practical exhaust tuning option with a convincing turbo sound.