These QA1 fits GM Pro Coil Systems are a great option for anyone looking for fully adjustable ride height and valving control. Choose a spring rate and adjustability that fits your driving style, adjust the valving to match and you are on your way. These shocks also utilize a fully threaded body that allows you to adjust your ride height for the perfect stance or to finely calibrate the weight balance for superior handling. Specially designed for QA1's Pro Coil Systems, the American-made lightweight high travel springs have fewer coils and a smaller wire diameter, resulting in increased travel due to the larger distance between the coils. They reduce unsprung weight and react faster, optimizing suspension performance. Multiple spring rate options are also available and have been successfully tested in various applications, from casual street driving to hard core applications. Adjustable Pro Coil System Features: Available in independent compression and rebound double adjustable, simultaneous compression and rebound adjustable, or drag "R" Series adjustable, Lightweight Billet Aluminum Coil-Over Shocks, High Travel Springs, Easy, Bolt-In Installation, Ride Height Adjustable, 100% Dyno Tested and Serialized, Serviceable and Rebuildable by QA1 Authorized Service Centers, Made in the USA, Used in drag , street performance, autocross, road and street rod applications, Sold in Pairs, Non-Adjustable Pro Coil System Features: Steel, Stock Appearing Coil-Over Shocks, High Travel Springs, Easy, Bolt-In Installation, Ride Height Adjustable, Used in drag , street performance, autocross, road and street rod applications, Sold in Pairs