Boyesen rsquo s revolutionary dual-stage reed design delivers more usable power than stock nbsp Your original one-stage reed Boyesen rsquo s one soft reed on top of one firm flow-through reed gives you a wide range of intake control Increased intake velocity Dual stage reeds Minor change gives major H.P. improvements Faster opening and closing Greater low pressure (Low-throttle) response Greater velocity and flow area Longer overall life No engine damage if broken Carbon pro has new carbon fiber reed for quicker response