RockJock's 3-inch lift rear coil springs for Jeep TJ Wranglers replace factory springs and are designed to work with RockJock Johnny Joint suspension systems or other manufacturer's lift kits as well. These springs are dual-rate and provide exceptional ride quality and height control. Finish is gloss black powder coat. Extensive research was done by RockJock to develop the perfect spring rate and quality of the coil springs. The results: they provide the best in comfortable ride and excellent performance off-road. If you off-road with heavy loads (large spare tire, camping gear, fuel/water, etc.) we most likely offer a better option of spring for your application. If you need help choosing the correct springs for your Jeep - just call the RockJock sales staff!