10-Pack Bearings R1810ZZ 5/16" x 1/2" x 5/32" 5/16 Bore BearingsR1810ZZ Shielded Ball Bearings 5 16" x 1 2" x 5 32" inch Lot of 10 Bearings R1810ZZ Shielded Ball Bearings, measures an inner diameter of 5 16", outer diameter is 1 2" and the width is 5 32", Made from high strength chrome steel for durability and performance each Comes with double metal shields (ZZ) to keep out dust and dirt, additionally, these bearings come pre lubricated with grease for smooth operation. R1810ZZ Ball Bearings Deep Groove Ball