The Bilstein B8 2003 BMW 540i Base Front 36mm Monotube Strut Assembly is a high-performance suspension system designed to improve the handling, comfort, and stability of your vehicle. It features a monotube gas-pressure design that provides a consistent, fade-free performance and a long service life. The assembly includes a 36mm strut body and a dust boot, as well as a bump stop, bearing plate, and upper spring seat. It is compatible with a range of BMW models, including the 2003 540i.