A wayfinder is a magic item used almost exclusively by members of the Pathfinder Society… so much so that the small device has become a calling card of sorts for its explorers and chroniclers. It is a handy exploration tool, able to function both as a compass and a light source.
It also contains slots that fit ioun stones. When a wayfinder includes an ioun stone in this manner, it reveals some new behavior which varies between wayfinders and depending on what stone is used.
A pathfinder’s wayfinder is a very personal symbol of both their commitment to the cause, and of their awards so far attained. Many choose to use their quest or level up rewards to enhance and customize theirs, making it truly unique and powerful. A pathfinder would never own several different wayfinders, however.