MSA All-Vision Diaphragm ChemOx Rebreather Mask
The MSA All-Vision Gas Mask was made for a variety of applications, including law enforcement and industrial use. This MSA Diaphragm Gas Mask, had two cheek exhale valves, a central speech diaphragm, and was used with a ChemOx rebreather system. This example was made by Mine Safety Appliances in the 1958.
Similar masks in my collection: MSA All-Vision Chemical Cartridge, MSA All-Vision Diaphragm Chemical Cartridge, Smith & Wesson No. 67, MSA All-Vision Acid Gas, MSA All-Vision Organic Vapors, German Kareta-Nova
"MINE SAFETY APPLIANCES CO.
"FRONT STRAP TO BE PULLED LAST"
"PATENTED NOV. 1, 1921"