The Spanish Máscara Antigas Stoltzenberg was a copy of the German Zivilschutz Vollblickmaske.  It was made for use during the Spanish Civil War under license from Chemische Fabrik Stoltzenberg.  This example is equipped with an Italian P.C. 40 filter.

Máscara Antigas = "Gas Mask"

Zivilschutz Vollblickmaske = "Civil Protection Full-Face Mask"

Chemische Fabrik Stoltzenberg = "Stoltzenberg Chemical Factory"