The H&R 99-03 BMW M5 E39 Sport Spring (Front Only) is a performance-tuned suspension spring designed to improve the handling and ride quality of BMW M5 E39 vehicles. It is made from chrome-silicone steel and is designed to reduce body roll and improve cornering. The spring is corrosion-resistant and is designed to last for the life of the vehicle. It is an easy to install upgrade that will give your BMW M5 E39 improved performance and handling.