At the heart of any true Jeep(R) suspension system are properly designed coil springs. Not everyone uses their Jeep(R) for the same purposes, therefore you need a coil spring that adapts to different terrains both on and offroad. By developing tuned sets of dual rate coils springs, JSPEC(TM) coils provide the best performance in any situation. Whether loaded down with gear for a weeklong expedition, running light for some rock-crawling fun or loaded with a few friends for a trip to the beach, JSPEC(TM) coils will provide the ride you want and the performance you need.