�@ STANDARD  SEAL SMT Bearings with suffix of 2RS are equipped with this type of seal.  The seal is Nitrile Butadiene Rubber(NBR) molded round a flat metal ring which imparts flexibility and strength to the construction and helps to control sealing performance.  The seal is compressed into a groove in the outer ring to ensure a tight joint without creating outer ring distortion.
�@ STANDARD  SHIELD SMT Bearings with suffix of ZZ are equipped with this type of shield, which is a formed metal disc, and is crimped into a shield groove in the outer ring, keeping a close running clearance with the inner ring.  Shields help to retain grease lubricant and prevent the entry of chips or large particles into the bearing.