Boyesen PRO-05 Pro Series Reed Pro series reeds use a carbon fiber top reed coupled with a durable fiberglass/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