... 25, OD 47, W 12MM3) Material: ZRO2,white color, SI3N4, black color , SIC black color4) Shield/closure: Open, ZZ, 2RS5) Tolerance ... , corrosion resistance and insulation, and can be used in extremely bad environment and special conditions. 2. Ceramic ... ball bearings can be widely used in aviation, spaceflight, navigation, petroleum, chemical industry, automobile, ...