Non-Fading Performance: Bilstein’s nitrogen-infused 46-millimeter monotube design with a floating dividing piston separating the gas and oil, provides consistent, non-fading performance; Durability you can trust on the road ahead. Digressive Valving: Bilstein’s patented digressive valving instantly reacts to changing road surface conditions for maximum comfort and control on and off-road. Enhanced Lane Stability: Bilstein’s 4600 shocks feature optimum grip and enhanced lane stability in day to day and extreme situations. Direct Fit: Tuned for each specific application to ensure optimal performance is achieved these 4600 series shocks fit 2011-2015 Durango without load leveling suspension and 2011-2015 Grand Cherokee without self-leveling (nivomat) suspension. Warranty: Warranty: Bilstein’s 4600 series shocks are backed by Bilstein’s limited lifetime warranty, ensuring their products are free from defects in design, materials, and workmanship.