Keyring

A keyring is a metal ring used to hold and organize keys. Such items appear in  Ultima Underworld II, Ultima VII Part Two: The Silver Seed and  Ultima VIII.

Mundane Key Rings
These items could first be found in the prison tower of Tarna. These simple hoops of metal served as a means of holding a large assortment of keys, but had no special properties to differentiate them from other containers.

Magical Key Rings
Later, should the Avatar meet with Isstanar of the Serpent's Fang outpost, the commander would make a gift of a magical keyring to the hero, once he ascertained that they were the prophesied Champion of Balance. This keyring forever held but two keys and any keys added to it would magically disappear. However the patterns of keys which had been used upon it would become magically imprinted upon the keyring itself, and any doors they would unlock would open to one of the two keys upon the ring. After landing on the foreign world of Pagan, the Avatar would find that many similar keyrings could be found throughout the land, with one being conveniently located in a barrel near the docks where they first awakened.

Trivia

 * In the Exult utility for Ultima VII, keyring-like functionality is available in  Ultima VII. By pressing the 'K' hotkey, the player may automatically attempt to use every key in their inventory on a selected lock.
 * A player-made modification for Exult known as the "Keyring Mod" adds an optional sub-quest to The Black Gate through which the Avatar might gain a magical keyring similar to the one featured in The Silver Seed.