Stasis box

From A Wheel of Time Wiki

A stasis box is a piece of technology from the Age of Legends. Few specifics are given, but they appear to be very difficult to damage. The contents of a stasis box are protected from the ravages of time; even living creatures have been found in stasis boxes, such as the gholam active during the time of the books. It is also believed that the container found at the Eye of the World containing the Horn of Valere and the Dragon Banner was a stasis box.