I would date this mask on late 20's/early 30's. It is a very early japanese army gas mask. This model seems to be a version of the US A.T. gas mask. As in other japanese masks, this one have rubberized fabric facepiece. It has internat Tissot tubes like in the US A.T. mask.
The conditions of this one is quite good, still elastic and the hose as well. The filter of this one is quite interesting as well.