These are the same Shocks packaged with MoparÆs lift kits. Order when upgrading from Performance series to Premium Bilstein, or when needing service replacements. The Performance shock is a twin-tube, high capacity hydraulic shock that features ten-stage velocity sensitive valving. White enamel finish; includes black boot. MoparÆs premium shock, jointly tuned with Bilstein, allows you to realize the most performance gain. The seamless monotube body contains a patented piston design and a high-pressure gas charge to quickly dissipate heat and minimize shock fade. Silver Zinc plated finish; includes black boot.