Known for their phenomenal spring ride performance, Skyjackers precision engineering gives you all the vigorous off-road handling needed while providing the smooth street riding characteristics that you demand. Skyjacker specifically engineered a progressive Rock Ready(R) 2-stage dual rate long travel coil. First Flex Rate stage delivers a comfortable ride with the ability to flex/expand during full articulation as the suspension drops (full droop). This keeps the coil springs seated in the upper coil mount/bucket and the tires in contact with the terrain. Second Ride Rate stage only engages after compression past Flex Rate. The process starts with 5160H chromium alloy material, an advanced method of shot peening and a presetting process. Each coil spring is blasted (shot peen) with hard steel pellets at very high velocities. Shot peening compresses the surface of the steel thereby increasing the tensile strength of the spring. Compressing the spring completely down to where the coils touch (solid height) is preset. This takes any fatigue or stress off the spring and eliminates sagging. Every coil spring has endured a cycle test to assure the very best in quality. A baked on powder coat provides an extremely durable protective barrier to prevent corrosion.