Front cartidge pair for Sport bike applications. Makes it easy to up-grade your factory internal fork assemblies without modification and exceeds all manufacture specifications. These replacement style cartridges are a perfect fit. The air in the shock reacts much faster than a standard hydraulic shock. Each cartridge has 2 chambers for lift, and 1 for rebound in axial alignment. This allows us to increase piston surface area, thus reducing air pressure required to lift. To dampen compression during hard braking we have add a booster spring.Delete no booster spring The result is a much smoother, and consistent ride and increased handling. Each kit is specifically designed to fit your bike without modification and exceeds all manufacture specifications.