S6902-2RS ABEC-5 Ball Bearing Stainless Steel and Ceramic Balls 15mm x 28mm x 7mm S6902-2RS Stainless Steel Ceramic Balls ABEC-5 quality Ball Bearing, this is a popular size that could be used in many application that uses this size 15mm x 28mm x 7mm, each bearing has 2 Rubber Seals to protect the bearing from dust or any possible contamination, also bearing is pre-lubricated with grease.