Powerflex Polyurethane Bush kit for BMW E83 X3 (2003-2010) Rear Anti Roll Bar Mounting Bush 18.5mm - PFR5-4609-18.5BLK - This part replaces OE number: 33503411987. Please check anti roll bar diameter before ordering. - Bush Size: 18.5mm - PRICE IS PER CAR KIT, NOT per bush. Powerflex usually price their bushes singly, but we have combined the QTY and price to keep it simple for you!