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 materials that meet our exacting specifications and is manufactured 100% at our Southern California factory. Features: Available in Blue Anodized Titanium Muffler with Carbon End Cap Massive Power gains throughout the RPM range. Huge weight savings New RTS (Rapid Tuning System) FMF uses the highest quality proprietary blend of alloy grade titanium made especially to our standards. Fitment: Husqvarna | KTM 2015-2019 2016-2018 Husqvarna FC250 FC250 2016-2018 2016-2018 Husqvarna FC350 FC350 2016-2018 2016-2018 Husqvarna FC450 FC450 2016-2018 2017-2019 Husqvarna FE250 FE250 2017-2019 2017-2019 Husqvarna FE350 FE350 2017-2019 2017-2019 Husqvarna FE450 FE450 2017-2019 2017-2018 Husqvarna FX350 FX350 2017-2018 2017-2018 Husqvarna FX450 FX450 2017-2018 2017-2019 KTM 250 EXC-F 250 EXC-F 2017-2019 2015-2018 KTM 250 SX-F 250 SX-F 2015-2018 2016-2018 KTM 250 XC-F 250 XC-F 2016-2018 2017-2019 KTM 350 EXC-F 350 EXC-F 2017-2019 2016-2018 KTM 350 SX-F 350 SX-F 2016-2018 2016-2018 KTM 350 XC-F 350 XC-F 2016-2018 2017-2019 KTM 450 EXC-F 450 EXC-F 2017-2019 2015-2018 KTM 450 SX-F 450 SX-F 2015-2018 2016-2018 KTM 450 XC-F 450 XC-F 2016-2018 2017-2019 KTM 500 EXC-F 500 EXC-F 2017-2019