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. Simultaneous Compression and Rebound Adjustment, Coil-Over, Lightweight Aluminum, Ride Height Adjustable, Spring Mounting Hardware Included, 100% Dyno Tested and Serialized, Revalveable and Rebuildable by the QA1 Factory or QA1 Authorized Service Centers, American Made, Precision Machined Aluminum Piston with PTFE Piston Band, 5/8" Centerless Ground, Hard Chrome Plated, Solid Piston Rod, Three Step Sealing System.