Maximize your spring tuning capabilities with these adjustable spring shims. Hidden-style shim is out of sight above the spring. Threaded steel two-piece design. Adjust the shim to where you want and then spot weld it. Features a 2-7/8" center hole to allow use with stock style shocks. Can be used with either 5"or 5-1/2" diameter springs. Allows 2" range of height adjustment.