From aftermarket sources you typically buy the two halves separately. The rollers can be caged in the outer or the inner ring; doesn't matter which.
5205 is the basic metric size for that bearing and the prefix and suffix (based on the manufacturer) tell you if it's the ring or the rollers and if there is flanges or not. There are multiple configurations for roller bearings. Obviously one half has to have no flanges so that you can assemble the thing. Look online for PDF catalog from a specific bearing manufacturer and it will explain their naming system and product configuration. Bower is part of NTN now and I can't remember if they have a Bower catalog or if it will be in an NTN catalog.
Because of the standardized metric bearing standards and 5205 ball bearing will fit right in there. So will a double row ball bearing. Just for illustration purposes, you want the roller bearing in there as it has a higher load capacity.