The Bilstein 38-228599 B3 Series Rear Coil Spring is engineered to restore the original ride height and handling precision of 2004-2010 BMW X3 models. Manufactured from high-quality chrome vanadium or chrome silicon steel, this coil spring offers superior break resistance and durability. Its innovative technical designs, including pigtail ends, minibloc shapes, and central force design, ensure optimal performance and longevity. The spring undergoes a hot setting process after forming to effectively prevent height loss over time. Finished with a corrosion-resistant coating, it provides protection against weather elements, enhancing its service life. Designed to meet or exceed original equipment specifications, the Bilstein 38-228599 B3 Series Rear Coil Spring ensures a precise fit and reliable performance, making it an ideal choice for fleet operators seeking to maintain vehicle suspension systems to factory standards.