Bilstein MDS (Modular Damping System) dampers are a premium motorsports product designed for professional road racing. The 2-way independent compression and rebound adjustment system provides 100 different setting variations for the ultimate in handling performance. The Easy Clip System (ECS) spring retainer system allows for rapid spring changes for easy at the track suspension tuning. MDS dampers are ideal for full-race car applications that demand exceptional versatility and fine tuning for track conditions. Bilstein MDS dampers provide proven performance and have taken many race cars to victory at races such as the 24 Hours of Le Mans and the 24 Hours of Nurburgring. 46mm Monotube Shock Absorber Porsche 911 2011, 911 2015-2014