Source: Tal'Dorei Campaign Setting Reborn

Wondrous item, very rare

These silver hand mirrors always come in pairs. When activated as an action, a mirror establishes a visual link with its paired mirror for 10 minutes, with the two mirrors acting as opposite sides of the same open window. The mirrors create this connection even if both are on different planes. When a single mirror of infinite transpondence is found, the GM decides where its paired mirror is and who possesses it. A random possessor and location can be determined by rolling on the table below.

d8 Location Possessor
1 Emon Seeker Odessa Tal'Dorei
2 Whitestone None; the mirror is in an empty dungeon
3 Kymal Sylker "The Millionaire" Uttolot
4 Westruun Realmseeker Eskil Ryndarien
5 Syngorn Ouestra, the Voice of Memory
6 The Elemental Plane of Water Khedive Xundi, Lord of Silver Silt
7 The Plane of Shadow A Remnant chosen
8 An untraceable location The Wonderworker

Once the connection between the two mirrors has been activated three times from either end, it can't be activated again until the next dawn.