... can be used in automobile,precision machinery,electric tools,power tools,sports apparatus,machines Item ... 440c/420c/304c ID (inner diameter)/Bore: 1 mm - 40 mm;OD (outer diameter): 3 mm - 80 mm; ... electric motors :60,62,63 series with open,Z,ZZ,RS,2RS,NR available2.material:chrome steel3.quality ... available7.Advantage:competitive prices with excellent quality High Quality bearings for electric motors