With sealed deep groove ball bearings have contact seals bearing type RS (one side seal), type 2RS (seal on both sides) and a non-contact seal type RZ (one side seal), type 2RZ (sealed on both sides). The bearing performance, grease and application with a sealed ring is similar with dust cap. However, there is a larger gap between inner rings in the bearing with dust cap; and there is no gap in the bearing with seal, the sealing effect is great with friction increased. These kind of bearing is used for office equipments, small and medium generators, vehicles, tractors, air conditioners, fans and etc.