Skyjacker offers two different styles of Add-A-Leaf springs that deliver lift and added strength. The Softride Long Add-A-Leafs will bring new life & lift to your fatigued insert stock springs. The Softride Technology uses only American steel and are shotpeened with hard steel pellets at very high velocities. This shotpeening compresses the surface of the steel to increase the tensile strength of the spring. This process allows maximum wheel travel, ride quality and life of the spring. The Heavy-Duty Add-A-Leafs are shorter and designed primarily for extra payload capacity.