In the Path of Exile 3.28 Mirage expansion, Astrolabes are a new endgame item type used on the Atlas to modify maps and manifest specific league rewards in specific quadrants.
Fungal Astrolabe
- Adds a Shaped Region containing Blight encounters to a quadrant of the Atlas

How to use it?
Speak to Eagon in your Hideout to right click this item and then left click a Map on your Atlas to apply a Shaped Region.

Example
- Your maps contain a Blight encounter
- 9% increased pack size in your maps

How to get it?
Fungal Astrolabe can drop from bosses within the Atlas after socketing an Originator Voidstone into the Atlas of Worlds.
Originator Voidstone: Bosses within the Atlas can drop Astrolabes and Exceptional Support Gems.