60/28-2RS Ball Bearing Set of 2 Ball Bearings Set of 2 sealed ball bearings 60/28-2RS size is 28 x 52 x 12 mm Bearings are made of Chrome Steel and can rotate up to 5,300 rpm with no problem, each bearing has 2 rubber seals to protect the bearing from dust or any possible contamination, also bearings are pre-lubricated with grease, Bearings are packed in the original manufacturer bag.