6200-2RS Sealed Ball Bearing 10 x 30 x 9 mm 10 Bearings 6200-2RS Sealed Ball Bearing, the inner diameter is 10mm, outer diameter is 30mm and the width is 9mm, Bearings are made of Chrome Steel, also bearings are pre-lubricated with grease, each bearing has 2 Rubber Seals to protect the bearing from dust or any possible contamination.