The ShM-41M (Russian: Шлем Маска - "Helmet Mask"), often erroneously known as the SchM-41, was a Soviet mask intended for infantry use. Similar designs were used throughout the Warsaw pact, and the ShM41M itself was exported to East Germany.
The ShM 41M is a Soviet gas mask made for the military. It is the most popular gas mask model in the Soviet military using the hood layout. The mask evolved and its construction held different markings. Several licensed copies of the mask were used in Warsaw Pact countries during the Cold War, including the Polish OM-14, MUA [with voice emitter], and the Bulgarian BSS-MO-4U. [It is important to note that East Germany never did produce their own masks. This is a common misconception. Instead, they imported masks from the Soviet Union, Bulgaria, and Czechoslovakia].
The origin of the Soviet ShM-41M dates back to World war II, where the 'SHM-1' gas mask was part of standard Red Army issue masks. The 'Hood Style' however dates back to World War I, pioneered as the 'Zelinski-Kumant' gas mask. The kit completed with an SHM-41/SHM-41m/SHM-41mu is called an RSH-4 kit, it has a bag which features three sections, for hose, filter and face piece. also a little pocket inside for antifoglens inserts and sidepocket for IPP-8 decontamination kit. filters would be EO-12/EO-14/EO-16(changed trough time) as a fact RSH-4 can be completed with SHMS face piece and MM-1 with same components.
During the 1970's, the ShM 41M gas mask was upgraded with a voice emitter for better communication between soldiers, and earhole cutouts on the sides of the mask to allow for effective use of radio equipment. The newly designed model was known as the PMG-2/SHM-66mu, and continues to see use within the modern Russian army.