Over the decades, FMF has seen an amazing transformation in the world of motorcycles and ATVs. The progression of the technology is one of the challenges that keeps them going. There is always one major force that keeps FMF motivated - throwing a leg over the bike and heading for the trails or the track. The biggest reward is knowing FMF is helping their customers get the most out of their riding experience. Replacement Quiet Core Spark Arrestor insert for FMF Q4 Hex and Powercore 4 Hex 4-stroke exhausts. Takes the noise out of riding, not the fun! U.S.F.S.-approved. Notes: For closed course competition use ONLY. Not intended for street use. Image is for display ONLY, actual product will vary by fitment.