FMF brings you the Slip-On Factory 4.1 RCT muffler, a top-of-the-range solution designed for GAS GAS, HUSQVARNA and KTM motocross bikes, combining performance, lightness and robustness. This model incorporates FMF's exclusive Resonance Chamber Technology™, applied both inside and outside the silencer body, to optimize throttle flow and improve the power curve throughout the rev range. Thanks to its Factory Forward Engineering design, the muffler is moved closer to the engine to centralize mass, while reducing its overall length to limit exposure to impact and improve handling in competition. Manufactured 100% in the FMF plant in Southern California, the Factory 4.1 RCT is designed with aerospace-grade materials to exacting manufacturing standards, guaranteeing exceptional durability and significant weight reduction. It is also equipped with the RTS (Rapid Tuning System), enabling rapid and precise adjustment without complex disassembly. This silencer is the strategic choice for demanding riders looking for pure performance and reliability on the racetrack.

Fits on

GAS GAS EC 250 F 2021

GAS GAS EC 350 F 2021

HUSQVARNA FE 250 2021

HUSQVARNA FE 250 2020

HUSQVARNA FE 350 2023

HUSQVARNA FE 350 2022

HUSQVARNA FE 350 2021

HUSQVARNA FE 350 2020

HUSQVARNA FE 450 2023

HUSQVARNA FE 450 2021

HUSQVARNA FE 450 2020

HUSQVARNA FE 501 2023

HUSQVARNA FE 501 2022

HUSQVARNA FE 501 2021

HUSQVARNA FE 501 2020

KTM XCF-W 350 2022

KTM XCF-W 350 2021

KTM XCF-W 350 2020

KTM XCF-W 450 2023

KTM XCF-W 500 2023

KTM XCF-W 500 2022

KTM XCF-W 500 2021

KTM XCF-W 500 2020