Made of high material for durability and stability Pressure can be adjusted by springs or air (nitrogen); Operation of the coil-over springs and air cylinder is helpful to reduce the shock No instruction included, professional installation recommended The suspension leg provides a smoother ride and better shock absorption management. The spring seat is insulated from the spring to ensure a quiet and comfortable ride The suspension shocks struts provides a smoother ride and better overall damping management Size:27cm A precision made part for strength and durability This suspension provides a smoother ride and better overall damping management Fits many other bikes with similar dimensions and poundage. 400LBS Measurement(approximately) : Eye center to center: 25mm/270mm/290mm Mounting hole diameter: 10mm Stroke value : around 50 mm Note: If you have any questions, please feel free to email! Due to the screen and lighting configuration, the colors may be slightly darker or lighter. This type of motorcycle shock absorber is designed to reduce the vibration caused by rough roads.