Recently acquired a second 3S mask. One by Auer, one by MSA. The Auer mask carries far less markings compared to the MSA, but Auer is mentioned on both masks. : r/gasmasks
MSA 805408 Advantage 1000 Series Full-Facepiece Respirators - Size: Medium, Hycar, Twin-Port, Reusable Gas Mask, Without Filters, MSA Advantage Cartridge Compatible: Papr Safety Respirators: Amazon.com: Tools & Home Improvement