The Bilstein B12 2009 BMW Z4 sDrive30i Front Suspension Kit is designed to improve the vehicle's handling and ride quality. It includes two Bilstein B12 Sport Shocks, two bump stops, and two strut mounts. The kit is designed to reduce body roll, improve steering response, and reduce road noise. The kit also includes all necessary mounting hardware and instructions for installation. The kit is designed to improve the vehicle's overall performance and provide a more comfortable ride.