... good quality 2.Big quantity, all series in stock 6312ZZ Ball Bearings, 6312ZZ bearings are made from Chrome Steel and can rotate ... to protect the bearing from dust or any possible contamination, 6312ZZ is self lubricated bearings (bearings are already greased).1. ... Item: 6312ZZ Chrome Steel - 2.6312ZZ Closures: 2 Metal Shields 3.Quantity: 1 Bearing ...