FMF Factory 4.1 Yamaha YZ 250F 10-13 not homologated muffler Gray, Not Homologated

The Factory 4.1 incorporates the latest in FMF Resonance Chamber TechnologyÔäó 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 is constructed from only aerospace grade materials that meet our exacting specifications and is manufactured 100% at our Southern California factory. Features: 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. Can be used with FMF or Stock OEM Header. For Yamaha YZ 250 F (2010-2013).