AirFX Rear Air Ride mono-shock for Star Motorcycles, Stratoliner and Roadstar models. The air ride kit is specifically designed to fit all mono-shock rear suspensions. Now you can fine tune your suspension for extreme cornering and braking and quickly adjust back to a comfortable cruising mode. Experience fast responsive, grip and true performance with our sport bike kits, all in a package not any larger than your stock shock. The air in the shock reacts much faster than a standard hydraulic shock. By lowering your bike you will change the center of gravity and your geometry. This makes a huge difference in handling. Each shock has 2 air chambers for lift and 1 for rebound in axial alignment. Rebound is set by adding air to the Schrader valve on the shock, allowing the rider to adjust the ride height and rebound setting.