bilstein 5100 gas shock set compatible with 01-10 chevrolet silverado 2500hd 4wd w/6" lift bilstein set of 4 shocks - compatible with 4wd vehicles w/6" lift. shock boots included with all shocks except in cases of special fitment. monotube gas charged for longevity, durability, and performance. all necessary washers, bushings, and nuts included. factory shock mounting bolts are reused for installation. bilstein's limited lifetime manufacturer's warranty protects against defects and premature failure.