8x15x5mm Ball Bearing - Shielded - Miniature8x15x5 Shielded Ball Bearing One Bearing 8x15x5 Shielded Ball Bearing, measures an inner diameter of 8mm, outer diameter is 15mm and the width is 5mm, a standard bearing size commonly used in a variety of industrial and commercial applications, made from durable 52100 alloy steel, commonly known as chrome steel, 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. 8x15x5