Empress Miniatures Russian No. 4 Gasmask?

[thestoats]

Hey guys,
So I'm looking at Empress Miniatures' new WW1 Russian stuff released at the end of July, and am curious about the gas mask worn around the neck of the third figure from left in the attached image. I believe this to be the No. 4 or 20-layer VZS mask, but I'm not sure. The goggles look like they have a more rounded geometry than the official pair for the No. 4 mask, but again I'm not quite sure.

If this is indeed the No. 4 mask, would anyone have realistically used them instead of the Zelinsky-Kummant by 1917? I understand they had a far poorer performance in comparison to the latter but continued to be used into late 1916 due to shortages of Zelinsky's model. However, I'd think by 1917 the Zelinsky-Kummant would be more prevalent, especially amongst elite units like the one this soldier is a member of. Obviously I don't know for sure though and would love for anyone else's feedback!