From publisher blurb:
Within this tome you’ll find the history of the dweorg, the dwarves of Aventyr! This new take on the classic dwarf brings to the fore the importance of tradition to these dwellers of the Underworld, from the deific Forging of the Dvergr all the way to the world-shaking portents of the nefarious drow of Holoth!
In Underworld Races: Dweorg you'll find....
new favored class options for every base class!
the fearsome Smithkin archetype, for warriors that love the forge as much as a good fight!
mundane items like bilosipid spice or the new liavous crystal building material
feats for dwarves too tough for a bit of cold or some heat!
enchanted wares like the surprising pocket anvil and instant forge!
a thorough rendition of classic dwarves to enhance the Pathfinder Roleplaying Game!