Looking for parts

Thank you for your patience during this busy season. I'm afraid I don't recognize this part. You mentioned that it's a cap for a balance, but I've never seen this design before. Is this the entire part, or has some of the component broken off? If this is only a partial component, then we need to see an undamaged version.

I think it might also be a good idea to see a picture of what this looks like installed so that we have some idea of its function.