Pro Series Carbon Fiber Dual Stage Reeds: Boyesen Pro Series Reeds combine breakthrough carbon technology with all the advantages of Boyesen's dual-stage Power Reed. The latest carbon fiber technology with all the advantages of Boyesen's patented dual-stage reed design. Utilizes a carbon fiber top reed and a durable fiberglass / epoxy bottom reed. Offers the quickest acceleration any reed can offer; maximize horsepower and torque. Responds quickly and accurately to changes in piston speed for smooth, dependable throttle response. No sacrifice in reed life like traditional carbon fiber reeds.