The Bilstein B4 2013 BMW X1 xDrive28i Front Left Suspension Strut Assembly is a high-performance suspension strut designed to provide superior handling and control for your BMW X1 xDrive28i. This strut is made with a monotube design, featuring a gas-pressurized construction that provides consistent and fade-free performance. The strut is also equipped with a special digressive piston that adjusts to road conditions, providing a comfortable and responsive ride. Additionally, the strut is corrosion-resistant and features a durable zinc finish for long-lasting performance.