Ancient Ring-shaped Coin

2.8g
20x12mm
I received this in a lot with mostly Roman, but also some ancient coins from Greece, Byzantine Empire, and India. I can't quite make out the lettering, but looks like a lot of X's.

Any help is much appreciated!

http://www.calgarycoin.com/reference/articles/celticrings/celticrings.htm

The Yoruba people of Nigeria also used to use "ring" money in ancient times. But it did not have any engravings as far as I am aware.

I have these:
also determined as ring money, but I am carefull about it

Hello,

Could you tell why it should be a coin and not just... a ring? Or something else?

Good stuff, thank you for the replies.

what you need is an expert, but I am not....