The best way to get an exact replacement is to give us the full part number on the invoice or despatch note that came with the original bearing. It is quite likely that you no longer have the paperwork. In that case, measure the bearing: the bore (internal diameter), the OD (outer diameter) and the width. Is the bearing open or does it have metal shields or rubber seals?
Identify any other features of the bearing. Does it have a flange on the outer ring? Is the inner ring the same width as the outer ring or wider? Can you see the retainer? If so, is it a steel retainer or made of a different material?
The fuller the description, the better. Is there a reference marked on the bearing? The reference may indicate the bearing material such as chrome steel or stainless steel and possibly confirm any other features such as the tolerance grade or the radial play.
If you are still not sure, send to the bearing to us although without the original reference, we may not be able to confirm tolerance grade, radial play or lubricant.