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
FITS- 2021-2023 GAS GAS MC 450F AND EX450F, 2019-2021 KTM 450 SX-F AND 450XC-F, 2019-2021 HUSQVARNA FX 450, 2018-2021 HUSQVARNA FC 450, 2018-2020 KTM 450 SX-F FE
