The Bilstein B4 2003 BMW 525i Base Wagon Rear Twintube Shock Absorber is a high-performance shock absorber designed to provide superior handling and stability for your BMW 525i Base Wagon. The shock absorber features twin-tube construction and a gas-pressure design, which offer increased dampening power and improved ride comfort. It is corrosion-resistant and features a high-pressure nitrogen gas charge for consistent performance. The shock absorber is designed for a direct fit and easy installation.