In the Mecca of winter gear design, Italy, someone probably had watched a few too many spunk flicks and thus this rather... unique design was born. Yes, these particular balaclavas were actually used in the Italian armed forces.
It's just about what you see in the picture - a white cotton balaclava, curiously with a zippered mouth. Your moustache won't snag to it, as there's a piece of cloth inside to prevent it. Just remember to fold it out of the way in use.
Used, but fortunately someone had the foresight to have these washed before discarding them to the surplus market.
Josh B.