Dial in your up-travel stops on your coil over suspensions. These easy to use Jounce Bumper Spacers allow you to control up-travel by simply placing urethane spacers between your factory bump stop and the shock body. The closed wedge design allows you to install the spacers without removing the spring or disassembling your strut. Take them out as easily as you put them in if you want to increase up travel. Each of the 4 spacers will decrease your up-travel by 8mm at the strut. California Residents WARNING