- 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
KTM -- 450 SX-F FE -- (2020, 2018, 2019); KTM -- 450 SX-F -- (2019, 2021, 2020); KTM -- 450 XC-F -- (2019, 2021, 2020); Husqvarna -- FX 450 -- (2021, 2019, 2020); Husqvarna -- FC 450 -- (2021, 2021, 2019, 2018, 2020); Gas Gas -- EX 450F -- (2021, 2022, 2023); Gas Gas -- MC 450F -- (2022, 2021, 2023)