Evolving from a history of worldwide racing dominance, Bilstein has developed the ultimate automotive performance suspension systems. To insure maximum performance, these systems utilize Bilstein's superior monotube gas shocks, featuring: Largest available piston diameter for greater sensitivity and percise control. Patented digressive piston head design and deflective disc valving instantly reacts to changing road conditions. Monotube design dissipates heat more effectively than a twin tube shock for cooler, more efficient operation and longer life. Lighter weight reduces wear and tear on suspension components.