Frequency Intelligent Exhaust system for the Audi S4/S5 B8 is a direct bolt on high-performance exhaust system made to get the most exciting soundtrack out of the engine.
The stainless steel exhaust and muffler internals are specifically designed for the ultimate experience.
The Fi-Exhaust system uses valves to direct gases exactly where you want them - through the muffler for a quiet comfortable drive or around the muffler for an intense and bang-on sound. Switching between the modes is done via factory sport button or optional remote control / mobile app.
Find out more from Fi-Exhaust website.