Bilstein B4 Series DampTronic gas-pressure shock absorbers are the ideal OE replacement for vehicles originally equipped with an electronic suspension system. This high-quality rear shock absorber is designed to maintain the factory ride comfort and handling characteristics while seamlessly integrating with your BMW's active suspension controls. Key features: Plug-and-play installation, constant damping power under any load, and high OEM quality standards. Package includes: 1x Rear Shock Absorber (Art: 20-303334). Note: Ensure your vehicle is equipped with the DampTronic/Electronic Adaptive suspension option before purchase.