Features： 1、Relieves the impact of the road surface,quickly absorbs the vibration generated by the bumps,and restores the bikes to smoother Cycle state. 2、Gives you smoother Cycle and better amping management. 3、2 system adjustments：Rebound \u0026 Preload. 4、 aluminum alloy body and steel coil spring. 5、Commonly used on downhill bicycles,mountain bikes and electric scooters. Specification： This spring shock absorber is the enhancement to any value.It will greatly improve the driving, handling and safety of your bikes. Features: Relieves the impact of the road surface,quickly absorbs the vibration generated by the bumps,and restores the bikes to smoother Cycle state. Gives you smoother Cycle and better amping management. 2 system adjustments：Rebound & Preload. aluminum alloy body and steel coil spring. Commonly used on downhill bicycles,mountain bikes and electric scooters. Specification: Length(eye to eye): 125mm / 150mm / 165mm / 190mm (optional) Material: Aluminum alloy + Steel Length (eye to eye) 125mm 150mm 165mm 190mm Spring Rate 550lbs 650lbs 650lbs 650lbs Storke Length 18mm 30mm 38mm 50mm Spring Length 57mm 82mm 93mm 115mm Spring Outer Diameter 46mm 46mm 46mm 46mm Installation Aperture 8mm 8mm 8mm 8mm Top/Bottom Bushing Length 24mm 24mm 24mm 24mm Weight 356g 478g 506g 664g Package List: 1* Spring Shock Absorber 4* Screw Package List： 1* Spring Shock Absorber 4* Screw