The mask is made out of black rubber with easily adjustable straps that come in both rubber and the more scarce stretchable fabric. The 4A1 is the civilian equivalent of the Israeli M15. The 4A1 built on the Model 4 (Model 4 was a copy of the German Dräger Simplex) by replacing the main exhale valve with a grid along with adding a voice diaphragm on citron models, and adding a drinking tube. The Israeli 4A1 is a civilian mask, made shortly after the Model 4.
