... . Ceramic bearings, of long life, with high precision. 1) Ceramic bearings: Special 639 ceramic bearings of high precision.2) OEM: We can provide OEM ... .5) Number of row: Double rows.6) Bore size and outside size: Standard size.7) Precision rating: P0, P6, P5, P4, P2.8) Logo ... ) Packaging: Wooden package, carton package. Special 639 ceramic bearings of high precision