Combo style outlet in Argentina

This accepts both Australian and EU style two prong plugs. I don't know what the third vertical blade is for. If it's for the EU style plug, it's not EU compatible, so I assume it fits three prong grounded Australian style plugs. I'll have to ask Paul. If anyone knows, please comment.

It also looks like the box can hold a combination of up to three switches and outlets.

image: 
photographer/artist/publisher: 
rad anzulovic