Features: The Factory 4.1 RCT incorporates the FMF Resonance Chamber Technology™ both internally and externally. In addition, we achieve a shorter overall length that is less susceptible to crash damage and complementary to our Factory Forward Engineering - moving the muffler closer to the motor to centralize mass. The Factory 4.1 RCT is constructed from only aerospace grade materials that meet exact specifications. NOTE: Will not pass 2025 FIM sound regulation.