The Genuine BMW Coil Spring Shim - 31331096664 is a small, metal component designed to be inserted between the coil spring and the strut assembly of a BMW vehicle. It is used to adjust the height and stiffness of the coil spring, allowing for a more precise and customized suspension setup. This shim is an authentic BMW part, manufactured to the highest standards for optimal performance and durability. It is compatible with various BMW models and is an essential component for maintaining the proper suspension system in your vehicle.