NOTE：Please refer to the picture and select right type of bearings before your order (Sealed or Shield on BOTH or SINGLE side of the bearing). Suffix on the bearing just for differentiating between Sealed and Shield type of bearing. It would not affect the use of our product. Description:Single-row, pre-lubricated, normal accuracy.Deep Groove Ball Bearings are one of the most widely used rolling bearings. They are used to accommodate radial and axial loads in both directions.With small friction and high-limit speed, Ball Bearings are cost-effective and require little maintenance.Can be used to build the track system or replace the wheel, widely used in door and window to track, or drive mechanical equipment. Selection Guide:Shields (Designation Suffix Z/ZZ) - High speed. Protect from dirt and debris.