Ramp control adds speed sensitive ending stroke/bottom out adjustability to forks. At high shaft speeds, the cartridge it mimics the addition of volume reducing spacers in the fork. At low shaft speeds it allows the fork to be more active.Fits 2013 and newer 40 Float ForksEasy installation with no lower-leg removalAdds speed-sensitive ending-stroke control and bottom-out force adjustabilityIsolate and tune bottom-out with minimal changes to initial and mid-strokeEasily change tune for different trails without tools MRP Ramp Control Cartridge Air Springs & Parts UPC: 702430173094