Quarantine Coloring Book
The Polish Maska Przeciwgazowa MP-6 was a copy of the Soviet ShM-41M, but used a different inlet/outlet assembly. It was used for industrial purposes. This example was made by Faser in 1968.
Similar masks in my collection: NVA ShM-41M, Russian ShM-62u, Polish MUA, Polish OM-14, Chinese TF-1