Wondrous Item, very rare
The user may open/lock any applicable thing (doors, gates, portals, e.t.c) Can open a portal to the Astral Plane, and the portal will close on a command word of choice. To exit the Astral Realm, the user must simply imagine where they want to go, and twist the key as if it were in a lock, then they will be teleported there (Does not apply to realms other then the one that the user last entered from)