Both inner and outer rings have a solid one-piece construction. Therefore, high accuracy and high rigidity are achieved, and mounting errors can be minimized. As separators are incorporated between the rollers for smooth rotation, these bearings are suitable for applications where rotational speed is comparatively high.       The outer ring is made of two split pieces, which are bolted together to prevent separation during transportation or mounting. So, handling is easy.       These bearings are very slim bearings having a small outside diameter, in comparison with the bore diameter, and a narrow width. The type with cage and the type with separator provide smooth rotation and are suitable for applications where rotational speed is comparatively high.