Ball Bearing 20x42x12 mm Double Shielded 6004ZZ Chrome steel Shielded Ball Bearing 6004ZZ Electric motor quality, Bearings 6004ZZ is a popular item that could be used in many application that uses this size 20x42x12 mm, each 6004ZZ bearings is closed with 2 Metal Shields, one Shield from each side, to protect the bearing from dust or any possible contamination, also 6004ZZ bearings are pre-lubricated with grease, Bearings 6004ZZ has industrial packaging.