When the S2000 (AP1 or AP2) is lowered it pulls the driveshaft out of the hub and the angle is changed. These spacers prevent premature bearing and CV joint wear associated with these changes. In some instances, lowering causes the driveshaft to vibrate due to the new position, these spacers will eliminate any vibrations. The two-piece design makes for an easy install without having to remove the driveshaft itself, includes all necessary hardware.