VAREX remotely adjustable mufflers utilize our patented technology to combine both the design of a stock muffler and a performance muffler into one single compact unit. A sophisticated, electronically controlled butterfly valve mechanism is implemented to redirect the exhaust gas flow and vary between the two muffler types. For a louder, more aggressive sound level, the exhaust flow is directed through the open path, producing maximum power with a robust sound level and near-zero resistance. For a lower sound level, the exhaust flow is directed through the chambered path (similar design as the stock muffler), producing a minimum sound level that gives you the best in-car comfort. The angle of the valve is controllable and can be adjusted to stop at various points between sports mode and silence mode. This gives you further freedom to set the optimal sound level according to your desired preference. The VAREX motor and gear sets are located on the top of the muffler, they work as an integrated unit to drive the butterfly valve open and close. The VAREX control unit features durable construction with water resistant plugs. Easy Installation, no hard-wiring required (in-car 12V socket included) for plug and play functionality. Stylish remote key fob included. Dual muffler control harness is available (sold separately).