The Bilstein B4 OE Replacement 11-15 BMW X3 2.0L/3.0L Front Left Twintube Strut Assembly is a high-quality, direct-fit replacement part for the front left suspension of BMW X3 models from 2011 to 2015. It features a monotube design with a gas-pressurized internal floating piston that provides superior damping performance and a high level of comfort. The strut assembly also includes a dust boot and a protective boot cover to protect the strut from dirt and debris. This strut assembly is made to meet or exceed the original equipment manufacturer's specifications for performance and reliability.