The exhaust system for the S4R version of the legendary motorcycle is led differently from other Monsters. Therefore we have developed a specially-designed Akrapovic SLIP-ON STREET LEGAL exhaust system. Unlike the stock system with two mufflers, our system has just one muffler, with two inlets and two outlets. The system is designed to deliver performance appropriate to a first-level exhaust tuning upgrade. In addition to performance, the Akrapovic SLIP-ON STREET LEGAL system delivers a major aesthetic improvement, as it fits beautifully into the lines of the naked Monster. The muffler has noise dampers installed in both inlets, so it conforms to exhaust system noise regulations for street use.