PLA The bottle opener prints separately and fits into the base of the handle on the axe. Bottle opener STL. :http://www.thingiverse.com/thing:1604606 I modified this to fit into the base of the handle on the axe AXE STL: http://www.thingiverse.com/thing:1632479 I modified the base to accommodate the bottle opener. I also added some 'viking' designs to one side of the face of the axe.