Ball Bearings 15x28x7 ( 6902-2RS ) Lot of 10 Bearings 10 Ball Bearings 6902-2RS, this is a popular size that could be used in many applications that uses this size 15mm x 28mm x 7mm. Bearings are made of Chrome Steel and can rotate up to 49000 rpm, each bearing has 2 Rubber Seals to protect the bearing from dust or any possible contamination, also bearings are pre-lubricated with grease.