With QA1's Proma Star single adjustable coil-over shock, you can easily adjust your compression and rebound valving and get the hard-core performance you need. One knob allows you to choose from 18 valving options that adjust both compression and rebound valving simultaneously, allowing total suspension control in one easy-to-reach location. Kit comes complete with everything you need. 100% Dyno Tested and Serialized. Revalveable and Rebuildable by the QA1 Factory or QA1 Authorized Service Centers. Precision Machined Aluminum Piston with PTFE Piston Band. Made in the USA. 150 lbs spring rate. Sold as a kit.