Increase ground clearance and wheel travel 1"-2" on most models, Rugged double-steel-wall construction, Progressive rate springs for comfortable ride and improved load-carrying capacity, Five-position spring pre-load adjustment for varying loads, Gas charged for fade-free operation, Durable fabric Shock Sox are included to protect shocks from rock, sand and mud damage, Shock Sox are easily removable with hook-and-loop fasteners for cleaning and adjustments, Not compatible with lift kits