The Bilstein B4 Series 19-135052 is a premium gas-pressure rear shock absorber designed to restore your vehicle's original ride quality and handling. Utilizing advanced Twin-Tube technology, this shock absorber ensures consistent performance and safety. It is an ideal OE replacement for BMW 3-Series and 1-Series models. Features include: constant damping power under any load, high power reserves for maximum safety, and OEM quality standards. This product is sold as a single unit. List of components included: 1x Shock Absorber (19-135052).