Boyesen PRO-114 Pro Series Reed For: KTM 250 SX 1999-2001; KTM 250 EXC 1999-2003; KTM 300 EXC 1999-2003; KTM 380 SX and 380 EXC 1999-2002 Pro series reeds use a carbon fiber top reed coupled with a durable fiberglass or epoxy bottom reed The top carbon reed is lightweight and resilient for crisp throttle response at partial throttle or low RPMs; the stiffer, bottom reed is ported to provide maximum flow and horsepower at higher RPMs Offers a quick and accurate reaction to piston speed for smooth dependable throttle response Increases performance without sacrificing the life of the reeds