Ford Focus Models Focus Mk3 inc ST and RS (2011-2018) Rear Diff Front Mounting Bush Insert - PFR19-1830BLK This is a polyurethane insert that fits into and fills the voids in original bush to stabilise the diff under acceleration. - NOTE: Price is for CAR KIT, NOT per bush… Powerflex price their bushes individually, but we have combined the quantities to make it simple!