10-Pack 61904ZZ 20x37x9 Shielded Bearing10 Ball Bearings 6904ZZ 20 x 37 x 9 mm Set of 10 Ball Bearings 6904 ZZ, measures an inner diameter of 20, outer diameter is 37 and the width is 9, a standard bearing size commonly used in a variety of industrial and commercial applications, Made from high strength chrome steel for durability and performance and can rotate up to 19000 rpm, each Comes with double metal shields (ZZ) to keep out dust and dirt, additionally, these bearings come pre