Shielded R156ZZ 3/16x5/16x1/8 inch Miniature Bearings Pack of 10R156ZZ Shielded Ball Bearings 3 16" x 5 16" x 1 8" inch Lot of 10 Bearings R156ZZ Shielded Ball Bearings, the inner diameter is 3 16", outer diameter is 5 16" and the width is 1 8", each bearing has 2 metal shields to protect the bearing from dust or any possible contamination, also bearings are pre lubricated with grease. Item: R156ZZ Ball Bearings Type: Deep Groove Ball Bearings Closures: 2 Metal Shields Lubrication: Self Lubricated (Grease)