From publisher blurb:
Zwerc are the most magical of all the dwarves of Aventyr. Their flight from the Grand Sculpting of the Underworld took them to the Amber Roads and into your Pathfinder Roleplaying Game! Read about this odd dimension, their connection to the Elemental Plane of Earth, how these magical dwarves fit into the history of Aventyr, and so much more!
In Underworld Races: Zwerc you’ll find…
a brand new player race for the Pathfinder Roleplaying Game!
favored class options for every role!
new equipment useful on the the Amber Roads like the amber attenuator!
new feats like Amber Magician, Zwerc Warrior, and more!
new magic items like the granite snack!
amber road disjunction, seek earthly transit, and more new spells!