Rubicon Express’ 2.5″ Piggy Back Reservoir Monotube shocks deliver superior performance over traditional twin tube hydraulic shocks. The vehicle specific ride tuning was derived after extensive dyno and real-world testing. The result is multi-stage valving that optimizes ride quality and handling characteristics for your specific application. The powder coated, monotube shock body is nitrogen gas charged to eliminate performance-robbing cavitation during compression and rebound, allowing the shock to dissipate heat more efficiently, drastically reducing shock fade. The external reservoir allows for additional fluid capacity and maximum heat dissipation.