FMF Racing Yamaha YZ250F 19-26/YZ250FX 20-26 AL F 4.1 RCT R. Carbon Cap Comp Sys w/SS MB Header/MIDThe 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 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 our exacting specifications and is manufactured 100% at