R10-2RS Ceramic Hybrid sealed Ball Bearing Chrome Steel and Ceramic Balls 5/8" x 1 3/8" x 11/32" inch R10-2RS Hybrid ceramic chrome steel sealed Bearing, R10-2RS Bearings with ZrO2 Ceramic Balls Electric motor quality, R10-2RS is a popular size that could be used in many applications that uses this size 5/8" x 1 3/8" x 0.344", each bearing is closed with 2 Rubber Seals, bearing is double sealed, one seal from each side to protect the bearing from dust or any possible contamination, also bearing is pre-lubricated with grease.