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 SCHMS Respirator

The SCHMS supposedly was designed by the East Germans to be a more effective mask that the military GP5 variant the M41, the lenses are designed so that a sniper or a soldier needing to use optics can raise them to the mask more easily. Adopted throughout the Warsaw Pact. The mask is also referred to as the "Deaths Head" mask due to it's skeletal appearance.

Soviet MM1 Respirator

A mask designed in the 1950s for Tank Crews, it uses two front lenses a voice diaphragm and takes a filter using the GP5 intake/outtake valve at the bottom of the mask.

Czech/East German M10M respirator

The M10 design was cloned from the American M17 and is visually very similar, many countries inside the Warsaw Pact adopted the design but the M10 was the only mask to be used by more than one Pact member.
Both East Germany and Czechoslovakia used two variants of this mask, the OM10 which was the basic mask with a voice diaphragm, and the M10 or M10M which also included a drinking tube.