3/8" ID x 5/8" OD x 3mm Height Ball Bearing3 8" inch ID x 5 8" inch OD x 3mm Height Miniature Ball Bearing 3mm thin Width 3 8" x 5 8" x 3mm Shielded Ball Bearing, measuring 3 8" x 5 8" x 3mm. Bearing is made from chrome Steel, 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. 3 8" x 5 8" x 3mm Shielded Ball Bearing Deep Groove Ball Bearing Closures: 2 Metal shields Size: 3 8" x 5 8" x 3mm Inner Diameter: 3