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