MR93ZZ Shielded Ball Bearings 3mm x 9mm x 4mm Lot of 10 Bearings MR93ZZ Shielded Ball Bearings the inner diameter is 3mm, outer diameter is 9mm and the width is 4mm, Bearings are made of Chrome Steel, each bearing has Double Shielded to protect the bearing from dust or any possible contamination. Bearings are packed 10 bearings in one plastic tube.