The Factory 4.1 RCT incorporates the latest in 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 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 our exacting specifications and is manufactured 100% at the FMF factory in Southern California. Available in Blue Anodized Titanium Muffler with Carbon Fiber End Cap Massive Power gains throughout the RPM range. Huge weight savings New RTS (Rapid Tuning System) FMF uses the highest quality proprietary blend of alloy grade titanium made especially to their standards. Can be used with FMF or Stock OEM Header