Front cartridge pair make it easy to upgrade your factory fork assemblies. Thesereplacement style cartridges are a perfect fit inside the stock forks, (fork modification required). 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. Each AirFX suspension kit is model specific for a custom fit to your bike.