FMF KAW KX450F'19-23 ANOD TI FCTRY 4.1 RCT S-ON CARBON END CAP 42371FMF KAW KX450F'19 23 ANOD TI FCTRY 4. 1 RCT S ON CARBON END CAP 42371 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 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