This is an Hermès Chaine d'Ancre bracelet. I was searching for it and finally found it at the Hermès directly-managed store in Haneda Airport about three years ago and purchased it (new). It's American size 5.5, which is Japanese size 10. I loved it and have worn it dozens of times, so there are some signs of use like small scratches, but there are no major scratches, so I think it's in good condition for a vintage item.