RI8516 ZZ Miniature Shielded Bearing 5/16" x 1/2" x 5/32"RI8516ZZ Shielded Ball Bearing 5 16" x 1 2" x 5 32" RI8516ZZ Shielded Ball Bearing, a standard bearing size commonly used in a variety of industrial and commercial applications, measures an inner diameter of 5 16" inch, outer diameter is 1 2" inch and the width is 5 32" inch, each Comes with double metal shields (ZZ) to keep out dust and dirt, plus its pre lubricated with grease so its ready to roll right away. RI8516ZZ Ball Bearing Deep Groove Ball