The R1-4-2RS is a sub-miniature imperial deep groove ball bearing engineered for high-precision performance in environments where contamination is a constant threat. Unlike shielded versions, the "2RS" designation indicates that this bearing is equipped with dual nitrile rubber (NBR) contact seals. these seals are reinforced with steel inserts and make physical contact with the inner ring, providing a superior barrier against moisture, humidity, and microscopic dust. This makes the R1-4-2RS the ideal choice for outdoor micro-electronics, medical devices, and high-performance hobby equipment that requires maximum internal protection and long-term lubricant retention.