The Bilstein B12 2009 BMW Z4 sDrive35i Front and Rear Suspension Kit is designed to provide superior handling and stability for your BMW Z4. The kit includes two front struts, two rear shocks, and a set of lowering springs to give your car an aggressive stance and improved cornering ability. The kit also includes a set of sway bar links to reduce body roll and improve overall handling. The shocks are designed to provide superior dampening and control over bumps and uneven surfaces, while the springs lower the center of gravity to reduce body roll and improve cornering. The kit is designed to provide improved performance and a comfortable ride, making it the perfect choice for those looking to upgrade their suspension.