The Factory 4.1 RCT incorporates FMF Resonance Chamber Technology™ both internally and externally Shorter overall length that is less susceptible to crash damage and complementary to FMF's 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 FMF's exacting specifications and is manufactured 100% at their Southern California factory Massive Power gains throughout the RPM range. Huge weight savings New RTS (Rapid Tuning System) Includes MegaBomb header Includes spark arrestor screen insert