RockJock’s ACOS (Adjustable Coil Over Spring) for the rear of 1997-2006 Jeep TJ Wranglers and LJ Unlimiteds allows you to raise and lower the height of your vehicle via a two-piece threaded upper bump stop. This allows you to adjust the ride height of your vehicle without having to buy new springs! Includes polyurethane bump stop and spring resting pad.