Ring of Gyges
The Ring of Gyges (Ancient Greek: Γύγου Δακτύλιος, Gúgou Daktúlios, Attic Greek pronunciation: [ˈɡyːˌɡoː dakˈtylios]) is a hypothetical magic ring mentioned by the philosopher Plato in Book 2 of his Republic (2:359a–2:360d). It grants its owner the power to become invisible at will.