The Planewanderer's Key is an incredibly powerful magical medallion.
While wearing this amulet, you can use an action to name a location that you have visited (while attuned to this item) on another plane of existence. Then make a DC 15 Intelligence check. On a successful check, you cast the Plane Shift spell. On a failure, you and each creature and object within 15 feet of you travel to a random destination. Roll a d100. On a 1-60, you travel to a random location on the plane you named. On a 61-100, you travel to a randomly determined plane of existence.
Currently this item is held by Khohros Nagumnath.
The planes which Sai has attuned currently is the Feywild and the Material Plane.
This amulet weighs ½ lbs. and has a fiery orange gemstone (jacinth) embedded in its center. Around the gemstone there is a dark metal inscribed with different symbols linked to the different planes of the multiverse which light up when the amulet is used to travel to the appropriate plane of existence. Outlining the obsidian there are leaf covered silver vines and hangs in a black leather thread.
Sometimes referred to by it's elven name in texts, Ladranaris Annon.