Men’s ring size unknown

Don’t know much about blood not know the size all sales are final so like situation think about the purchase before you make it because we’re not in a world where we can just go and for on our purchases cause we decide we don’t want it anymore. I do not know the size the last photo I took is of a nickel completely in the circumference of the ring so that is how big it is. It has markings on the inside. I cannot tell what it says. My eyesight is not the best without glasses. It is very heavy and it is shiny and it belonged to my grandpa. That’s all I know.