Made this today while messing around with an MSA Ultravue and a GP-5 gas mask. I feel it would be a good part of a Metro 2033 Cosplay, as I can see someone taking a modern mask and having to "shop" older, but more common, Soviet mask parts onto it. The original mask itself is the black section, the brown part is the GP-5 mechanism, and the filter I believe is Czech, although it has multiple languages on it. Probably not going to sell it, might just return it to base parts and reuse them.
EDIT: I'm not the only person here who names their various items, am I?