In the Manga, the key is depicted to be an ordinary golden key with the crest of the Archer, an arrow crossed with a line near the triangular tail, stamped on its bow. In the Anime, the key is still depicted as gold but is designed more intricately. The bow of the key is circular with a white circle in the middle, stamped with the crest of the Archer, colored in green while the handle and blade are designed to look like an arrow.
While in possession of the key, a Celestial Spirit Mage may be able to summon the Archer Sagittarius by reciting the quote, "Open the Gate of the Archer! Sagittarius!". This summons Sagittarius, a man wearing a horse suit, carrying a bow with a quiver of arrows strapped on his back.