OEM bump stops and dust bellows will not fit this shock absorber. Included with the shock absorber is a rubber bump stop (tan color) installed on the shock shaft. The dust bellow (blue plastic sleeve) is specific to the shock absorber and is support by a metal washer that sits on top of the piston shaft. These parts must be used when installing this shock absorber. Bilstein designed this shock to use OEM upper and lower mounts on E9X 3-series models.