Finnish Siviili Kaasunaamari M/31

The Finnish Siviili Kaasunaamari M/31 was made of orange rubber covered with gray stockinette. This example is missing some of the straps and was made by Nokia in 1931.
Siviili Kaasunaamari = "Civilian Gas Mask"
Similar masks in my collection: British C7, Swedish Type 15, Swedish Type 19, Swedish Type 32