Check the listing for details. Rare Soviet Aviation Pilot KM 30 M Mask Size 5 Large. Listed at 157.50 USD. Original, vintage Soviet aviation KM-30M pilot's oxygen mask. Extremely rare on the market, because it was produced in very short period of time, in very small quantity. The mask was never used, new old surplus. The set includes KM-30M mask size 5. Great opportunity to add this extremely rare mask set to your collection. Excellent condition, considering that the mask's set age-over 60 years old. Some information: KM-30 (ShL-61 & ZSh-2) Next major Russian oxygen mask upgrade since KM-16. Pressure-demand type. This is one of the first Russian masks that allowed attachment of an occipital bladder, although the bladder was worn on the back of the pilot's head over the leather helmet. No built in microphone, pilots relied on the La-3 and La-5 neck mounted microphones. Used a pressure regulator mounted at hose end. A complete issue included the mask, its occipital bladder, hose-end regulator, and a carrying satchel. Occasionally found today without the hose-end regulator or bladder assembly, but still rare in any configuration. KM-30M (ShL-61 & ZSh-2) presumably an improved version of KM-30, since 'M' represents the Russian term for ‘modification'. We are now able to create special listings for multiple items with a complimentary price discount for multiple purchases, including providing you with a new combined and lower shipping cost. Please do not hesitate to contact us to learn more about this new offering!Happy Collecting!