Self Align Bearing has outer ring that can swivels around the geometric axis of the bearing without harming the bearing componenets, high vibration environment will lead to the failure of any regular radial bearing in a fraction of the anticipated lifetime of the bearing, the Self Aligning Bearing type will perform great in such environment, they can come in Ceramic Ball Bearing, Self Aligning Ball Bearing, sealed bearing, shielded bearing, full ceramic, please browse our website and buy online, we ship same day.