Makes it easy to upgrade your factory fork assemblies. These replacement style cartridges are a perfect fit, without any modifications. Each cartridge has two chambers for lift, and one for rebound in axial alignment. This increases piston surface area, reducing the air pressure required to lift the bike. The result is a much smoother/consistent ride and increased handling performance. Fork top cap covers are provided to hide the air connections. Each AirFX suspension kit is model specific for a custom fit to your bike.