6307ZZ Shielded Ball Bearing 35mm x 80mm x 21mm 6307ZZ Shielded Ball Bearing, material is Chrome steel, 6307ZZ is Electric motor quality, each 6307ZZ bearings is closed with 2 Metal Shields, one Shield from each side, to protect the bearing from dust or any possible contamination, also 6307ZZ bearing is pre-lubricated with grease, Bearings 6307ZZ has industrial packaging.