The Koni Special Active Shock FSD 11-16 BMW 5 F10 RWD Rear Left is a high-performance shock absorber designed to improve the handling and stability of the BMW 5 F10 RWD. It features an adjustable frequency selective damping (FSD) technology that allows for a wide range of damping forces to be applied, allowing for improved performance and control. It also features a progressive spring rate that increases the shock's effectiveness as it compresses, providing a smoother ride with improved control and stability. The shock has been designed to provide improved cornering, body roll control, and overall stability.