Swedish

 Among HEMA enthusiasts it is relatively well-known fact that some really strange headgear can be found in Swedish fencing manuals, e.g. this fencing mask. [1] But even armed with this knowledge I was really surprised when I saw this.

A damaged specimen [2]

 At first it isn't even clear that we see an incomplete and heavily damaged headgear. Even after reading... well translating the Swedish text the situation hasn't changed too much. Fortunately some additional search has provided much needed photos showing better preserved specimens from the Swedish Royal Armoury. [3]

The best preserved specimen
(LRK 6446)

  The museum provides some useful data on these masks, e.g. weight 2667 g (LRK 22427), 1819 g (22426) and 3043 g (6446). And finally the absolute favorite!

The maximum protection!!! [4]

______________________________________________________

1. Instruktion i sabelfäkting till fots (1893) Source.
2. Livrustkammaren 58997.
3. Sabre fencing masks from Livrustkammaren (LRK 22427, 22426, 6446). Source: Wikimedia.
4. LRK 6486.