FMF has made it clear that we love 2-strokes, and we're backing it up by adding an all-new muffler design to our line-up. Don Emler headed up the Q-Stealth personally, because he loves to ride 2-strokes and is dedicated to reducing noise levels. The Q-Stealth is living proof FMF is the only exhaust company committed to bringing new technology to the 2-stroke enthusiast.Quiet on the trail as well as on the sound meter. No power loss. More packing volume-longer time between repacks. USFS approved spark arrestor. AMA and FIM enduro legal. Spark Arrestor: Internal. Weight: 4.0 lbs. For Gas Gas 250, 300 (2014-2015).