For 1997-2006 Jeep TJs, these 4" lift coil springs replace factory springs and are designed to work with RockJock Johnny Joint® suspension systems or other manufacturer's 3 to 5-inch lift kits. This set features our standard rate front springs and increased-rate rear springs for improved ride and vehicle height control when loaded.Extensive research was done by RockJock to develop the perfect combination of rates and quality of the coil springs. The results: they provide the best in comfortable ride and excellent performance off-road. Powder coated finish.