Scope of delivery: - Flap control ø 70mm 2.75" open vacuum controlled exhaust flap stainless steelDescription: - the flap is open and closes with decreasing vacuum - Inner diameter ø 70mm - Outer diameter ø 81mm - is made of stainless steel - adjustableWe offer you inexpensive, high-quality stainless steel flap controls for your exhaust system. These are then used to regulate the volume of the exhaust.The way it works is quite simple:When closed, the exhaust gases are routed through the silencer; as soon as the flap is open, part goes through a continuous pipe, making the exhaust louder. The vacuum-controlled flap is closed in the vacuum range, then opens as soon as the vacuum decreases or with turbo engines goes into overpressure. A hose is routed from the intake manifold to the vacuum chamber of the flap, or the flap is controlled via remote control or switch. A pulse valve is installed in the hose for this purpose.Suitable for: - Exhaust systems with 70mm diameterOptional matching parts: - Remote control for flap control