Valvetronic Design Porsche Exhaust Valve ControllerWelcome everyone to a revolution in the market. The Porsche OEM exhaust valve controller by Valvetronic Designs. This setup is a complete plug and play unit for most Porsches that give the driver full control over the exhaust valves. For cars like the 991. 1 Carrera S without sports exhaust, the factory exhaust has valves, but there is no button to open and close these valves. Our controller puts the power in your hands. These Controllers FIT ALL