Upgrade your rear end with QA1’s Pro-Rear System. Available in double adjustable, single adjustable and ride sensitive valving non-adjustable options, each adjustment has been carefully defined to provide the ideal force curve to maximize performance. With evenly spaced valving changes throughout the adjustment range, there are no jumps when adjusting between any two clicks. These Pro-Rear Systems are commonly used in drag racing, street performance and street rod applications. Available in simultaneous compression and rebound single adjustable (DS), independent compression & rebound double adjustable (DD) or ride sensitive non-adjustable valving options. These coil-over shocks are made with lightweight aluminum and offer ride height adjustability. All mounting and spring mounting hardware included. Revalveable and rebuildable by the QA1 factory or QA1 Authorized Service Centers, they are 100% dyno tested and serialized and made in the USA. Kit includes: (2) Proma Star Shocks or Aluma Matic Shocks (2) Linear or Variable Rate Springs.