Engineered to racing specifications, tested and proven over decades on winning racing teams. Integrating the highest-level technologies into an affordable street-spec coilover, our systems are a perfect, affordable solution for your daily driven performance vehicle. Built with daily driven sports cars in mind, our Pro-ST shock absorbers are shorter than factory, lowering the vehicle approximately 3- inches while still retaining full shock travel. This, coupled with the 12-way damping adjustability and stiffer springs, allows you to adjust to the perfect setting for the driving environment. Large 52mm seamless carbon steel mono-tube shock bodies provide strength and provide room for a larger hydraulic piston and valves, more shock oil, and an enlarged nitrogen chamber. All of these upgrades add up to huge jumps in compression and rebound response, vastly improved handling characteristics, and extreme durability even in the harshest of conditions. Externally, the shock bodies are threaded along their length to fit spring preload adjustment collars and the internally threaded lower shock mount and collar. This allows for independent changes in ride height and spring preload, giving the ability to tune each corner's weight to achieve optimal 4-wheel corner balance without sacrificing ride quality. Additionally, the shock body and threads are protected from the elements with gold-colored zinc electroplating. After rigorous testing, we chose to fit linear rate springs instead of progressive. Featuring spring rates of 10kg/mm up front and 8kg/mm in the rear, the linear spring offers more consistency under all different measures of weight loading while cornering and hitting bumps. This offers the most predictable vehicle feedback in all driving situations. Each spring is made from the highest quality AE9254V Chrome Vanadium forged to work with our oil-nitrogen filled strut to provide the greatest possible balance of street and track performance.