The Bilstein B4 2003 BMW Z4 2.5i Front Left Twintube Strut Assembly is a high-performance suspension system designed to provide improved handling and stability for your BMW. This strut assembly is an OEM-quality replacement part, featuring a twin-tube design that helps to reduce wear and tear on the suspension components. The assembly is made from corrosion-resistant materials, and is designed to last for years of reliable performance. It also comes with a lifetime warranty, so you can be sure that your BMW will be able to handle the toughest of roads.