This is a Polish copy of the American M17A1 gasmask, which was a surprisingly common thing to do in the East Bloc. Comes with a bag that's also a copy of the US model, albeit naturally a bit more nasty.

The MP-4 is a direct copy of the American equivalent, with the filters hidden inside the cheeks. Adjustable to all head sizes with the elastic straps. Being a military mask, you can use a helmet with this... at least on the paper.

It comes with spare filters and spare eye pieces.