Backside anti-roll bar for ball-bearing roll bar mounting system and redesigned to work well with the X4 rear suspension system hands. The anti-roll bar system is mounted towards the back bulkheads via bearings from outside for extra-smooth motion as well as for quick & simple modifications and adjustment. The roll bar turns in ball-bearings for maximum precision and free movement. Anti-roll bar height is adjustable via a screwââ¬Â¦ fast & effortless. Anti-roll bar has laser-engraved stripes (corresponding to club thickness) for easy identification.