What is fisherman ring?

The Fisherman's Ring is a special gold ring worn by the pope, which is engraved with the name of the pope in raised letters. It is called the Fisherman's Ring because it has an image of Saint Peter, a fisherman, with the keys of heaven. The ring is used as a seal to authenticate certain official papal documents. When a pope dies or resigns, the Fisherman's Ring is traditionally destroyed to show the end of that pope's reign. A new one is then created for the subsequent pope. The first mention of this ring comes from the Middle Ages, and it is considered one of the oldest and most treasured symbols of the papacy.