1.No seal, durable, no need for frequent maintenance, not waterproof2.Low coefficient of friction, high ultimate speed.3.Mainly bear radial load, but also can bear a certain amount of axial load.4.Applications in precision instrumentation, low-noise motors, automobiles, motorcycles and general machinery. 2RS-Rubber Seals Deep Groove BallBearings1.Performance:Waterproof, dustproof, silent, corrosion resistant.2.Applicable environment:Suitable for high-speed silent environment.3.Applications automotive, machine tool spindles, construction machinery, large agricultural machinery. ZZ-Metal Seals Deep Groove Ball Bearings1.Performance:fast heat dissipation, high temperature resistance, high speed.2.Applicable environment:Suitable for high temperature and high speed environments.3.Applications internal combustion engines, electric motors, agricultural machinery, construction machinery