Double row cylindrical roller bearing with fixed inner ring & sliding outer ring

What are the features and benefits of these bearings?

With a fixed inner ring and a sliding outer ring, these bearings are commonly found in gearboxes and pumps. They are able to run directly on the outer housing without an outer raceway, in applications designs where space is limited. 

The double row of cylindrical rolling elements means that these bearings can carry twice the radial load of the single row variety, but are not able to take any axial load in either direction.