Backside anti-roll bar for ball-bearing roll club mounting system works with back suspension hands. The anti-roll bar system is installed to the back bulkheads via bearings from outside for extra-smooth movement and for fast & simple modifications and modification. The roll bar turns in ball-bearings for optimum precision and free motion. Anti-roll club height is adjustable via a screw... fast & easy. Anti-roll club has laser-engraved stripes (corresponding to club depth) for simple recognition. Can be used with #303434 Aluminum Anti-Roll Bar Bushing o2.0mm - 6mm (2) Fits X4 & X4F