This is NU series, if you are interest in other bearings, please see other items

NU design
The outer ring of bearings of the NU design (has two integral flanges and the inner ring is without flanges. Axial displacement of the shaft with respect to the housing can be accommodated in both directions within the bearing itself. The bearings are therefore used as non-locating bearings. For manufacturing and maintenance reasons, the two outer ring flanges of large-size bearings of the NU design which are identified by a Drawing No. may not be integral but take the form of loose flange rings.