No, but there's a lot more to it than just size. What is the material, buna or viton? Durometer rating "stiffness"? I'd take it apart, and order the proper O ring from McMaster Carr. Measuring and matching the size is the easy part, making sure it's correct material is more important.
O-rings are pretty standardized. Can you remove it and take it to an auto parts store, Harbor Freight, etc ? They sell all different sizes of o-rings. Hydraulic oil isn't too aggressive so nitrile, viton, plain rubber, etc o-rings are fine.
It is very brittle. I saw a Youtube video where 1 guy had a similiar jack. He was changing the same o-ring. He showed the o-ring he ordered and it was a size 208. Im gonna order that one and hope that's it.