Zone Offroad torsion bar keys are made in the USA and are 100% resonant frequency tested to ensure a solid casting. Once tested the keys are CNC machined to ensure the proper amount of lift for your vehicle. These keys are designed lift the front of your truck 2 inches. Zone Offroad shock extensions are highly recommended.Zone Offroad shock extensions (C5202) or longer shocks listed in the accessories are required for this kit.