Backside anti-roll club for ball-bearing roll club mounting system works with straight back suspension system hands. The anti-roll club system is initiated toward back bulkheads via bearings from outside for extra-smooth movement and for fast & effortless alterations and modification. The roll bar turns in ball-bearings for maximum accuracy and free movement. Anti-roll club height is adjustable via a screw... fast & simple. Anti-roll club has laser-engraved stripes (corresponding to club level) for simple recognition. Works extremely well with #303434 Aluminum Anti-Roll Bar Bushing o2.0mm - 6mm (2) Fits X4 & X4F