The Koni Special Active Shock FSD 12-17 BMW 2/3/4 Series RWD w/ M-Technik Susp Front is a high-performance suspension system designed specifically for BMW 2/3/4 series RWD cars with M-Technik suspension. This system utilizes Koni's Frequency Selective Damping (FSD) technology to provide superior handling and control, while also offering a comfortable ride. The FSD technology allows the shock absorbers to adjust to different road conditions and driving styles, providing a customized suspension for each driver. The Koni Special Active Shock FSD 12-17 BMW 2/3/4 Series RWD w/ M-Technik Susp Front is designed to offer maximum performance and stability, while still allowing for a comfortable ride.