Belgia n Ademhalingsmasker S.B.A.

The Belgian Ademhalingsmasker S.B.A. had a large speech diaphragm and a unique finger-shaped sweat reservoir located under the chin.  At the tip of the reservoir was a valve to drain any accumulated moisture without removing the mask.  Designed for industrial use, this example was made by Société Belge de l'Azote in 1939.

Ademhalingsmasker = "Respiratory Mask"
Société Belge de l'Azote = "Belgian Society of Nitrogen.

Similar masks in my collection:  N/A