... precision,good quality. Miniature Deep Groove Ball Bearing:1.metric series, Bore Dia 1-12mm 68xx, 69xx, MR8x, MR9x, MR6x.2.metric ... 2-9mm Fxx, MFxx series.3.inch series, Bore Dia, 1.984-9.525mm, Rx series.4.inch R-Flange series ... , Bore Dia, 1.984-9.525 FRxx series.5.Miniature Thrust Bearings series ...