From publisher blurb:
Construct Mechanus introduces a new player character race, the mechanus. Inside this 24 page PDF you will find two different mechanus races, two classes, an assortment of feats, and a selection of firearms (using previously released OGC firearms rules).
This new supplement helps players and GMs to bring "steampunk" to their fantasy games. Construct Mechanus is the first in a series of supplements designed to create a non-standard world setting.
For campaigns looking to keep a more standard fantasy feel, Construct Mechanus allows the GM to construct the perfect villain(s) for use in planar adventures.