QR Code Link to This Post Same some bucks with this newrly new FMF with less that 200 miles on it. Fits Honda CRF450X years '05 to current. Please contact me with any questions and thanks for looking. Brian 6ome6 836 781one. As the pioneer of quiet performance mufflers, FMF raised the bar again in 2007 with the second generation of Q series mufflers, the Q4.Built from the ground up, the Q4 is a completely new design, engineered for maximum performance while maintaining a sound level at or near 93 dB on most models. The Q4 is the market leader for low sound / high performance. Less sound equals more ground.Q4 Details:-The Q4 incorporates Factory Forward Engineering to move the muffler closer - centralizing the mass for improved handling characteristics. -The new Hi-Flo formed end cap reduces weight and is less prone to damage. -The Q4 has an anodized aluminum canister and is lighter and quieter than the original Q model slip-on. -All Q4 exhausts utilize a maintenance-free -USFS-approved turbine type spark arrestor so there is no screen to clean or burn out. -The Q4 employs free-flowing internal baffles and chambers, advanced sound-absorbing materials and a reduced weight. -Max Sound output 96 dB, most models below 93 dB. -Constructed from aircraft-grade aluminum and high-strength stainless steel. -Use with stock or FMF header.