X-Wing, AT-AT/ TIE Helmet Oxygen Mask Attachment

This is the oxygen mask "butterfly connector" receiver from an APH-6B (the helmet that the x-wing and therefore TIE and therefore AT-AT driver helmets were modeled after), minus the part where the mask would connect as that is unnecessary and filled in anyway. The rounded edge is towards the back of the helmet, the straight edge is towards the front. This was made to increase the accuracy of http://www.thingiverse.com/thing:813532

The second revision .stl file has holes in case your rivets do