The TeraFlex JK 4dr: 4in Coil Spring Base Lift Kit includes just the basic lift components only and doesn�t have the drivability of a full suspension system. REQUIRES adjustable control arms and adjustable front track bar to correct suspension geometry. An adjustable rear track bar is recommended. We recommend Falcon Performance Shocks or TeraFlex 9550 VSS Shocks. These are the only shock absorbers engineered to work with TeraFlex lift coil springs to improve both compression and rebound for optimal vehicle stability. Coil Spring Base Lift Kits are offered with TeraFlex 9550 VSS Twin-Tube Shocks or without shock absorbers. Falcon Performance Shocks are available separately.