Chinese Gas Mask:
As far I know this is the only example I know about a chinese gas mask used in the sino japanese war. China used exported gas masks that were made in europe. Those models have got the marks from the european factories, but this one has marks in the rubber and exhale valve from the chinese factory, named CHICO.
I arrived the conclusion it is a chinese gas mask made in the late 30's. It looks like the czech FM3-d made by Fatra, but this one, guiding myself by factory's marks in the rubber and exhale valve and some other differences, I would be sure to confirm it was made in China by a company named Chico. I would catalog it is as an version without license.
This one is the only example that proves they made gas masks, in low quantities due of the shortage of surviving examples. Another interesting fact is that it was captured by the japanese Army and reused by them, the filter has been covered with japanese instructions and with the slogan: Greater East Asia War Victory Gas Mask. Prior to 7-December-1941, the fracus in China was eeferred to as an "incident" and not a war. Today it still referred as an incident in Japan.
The tag of "arrow & gear" is the symbol of Chinese Arsenal (Republic of China):
Detail of the factory's mark in the exhale valve:
The filter is marked by the company CHICO as well, it has a rubber protection piece. Also, as I mentioned before, it has instructions in japanese on it.
In the instructions we can read the slogan: ''Greater East Asia War Victory Gas Mask''. Also it is marked Showa18 (1943):
There's a phrase in the filter's rubber cover, something like Chico Insturstry Co.
The harness use springs instead of elastic straps as the FM3-d uses:
There's some photos about chinese troops using exported gas masks:
This ones seems to be exported german models:
This other seems to be exported belgian models: