A rough guess is it's a size 6 or 7. Primarily made up of silver while the middle threads going around the ring are made of gold. On the inside is one large circle with three separate inscriptions, the first being 925 which itself I'd circled. The second being the makers mark bib which is also sorts circles but the letters are more arranged in a pyramid shape. And the third being the word italy.

Honestly not sure. It was purchased along with the entire contents of a storage unit at a auction.