Oxygen mask of the semi-closed type. Currently, continuous oxygen supply systems use masks with an oxygen receiver and a sponge exhalation valve. The use of a semi-closed mask made it possible to significantly increase the percentage of oxygen in the inhaled air and reduce its useless consumption. An example of a semi-closed type mask is the KM-19 type mask. The KM-19 mask is used when using oxygen from on-board oxygen continuous supply devices such as KP-32 and KP-56.
The KM-19 mask can only be used up to a flight altitude of 10 km. A very rare oxygen mask from the 1950s!!! The item "Oxygen mask of a military pilot KM-19.USSR 1950s" is in sale since Thursday, February 4, 2021. This item is in the category "Collectibles\Militaria\Militaria (Date Unknown)\Air Force". The seller is "aviator-man" and is located in Moscow, . This item can be shipped worldwide.