Polish OM14 Respirator

Polish OM14 Respirator with a large EO14 filter.
The mask is very similar to the East German SCHM41 in terms of design and filter type. The differences being the OM14s filter is more of a water canteen shape and the metal on the inhale/exhale valve is a different material. The mask also appears to be actually white where most GP5 style masks are light grey.
The mask was used by Poland during the Cold war.

Soviet/Russian GP5 Respirator

The Soviet GP5 Civilian respirator is the most common mask on the surplus market and perhaps also the most famous gas mask ever made, it's a simple latex hood with two lenses and a filter intake and outlet valve at the bottom. Chances are if you see a TV show or film using cheap gas masks, they'll use the GP5.