RKKA gas mask BN-MT4, a rare variant with early war modified mask MOD-O8 which got a new name O-9 after adding screw adjustment to the valve system to fit with a separate hose. Note that normal MOD-O8 mask has a permanently fixed hose to the valve system. The newest filter-canister developed in the end of '30s to change the previous bigger in size T-4 ( type 4) filter. The filter is produced in the 1941 year, and then tested again and remarked in the 1943 year. Rare transitional completed Soviet ww2 gasmask.
RKKA gas mask BN-MT4, a rare variant with early war modified mask MOD-O8 which got a new name O-9 after adding screw adjustment to the valve system to fit with a separate hose. Note that normal MOD-O8 mask has a permanently fixed hose to the valve system. The newest filter-canister developed in the end of '30s to change the previous bigger in size T-4 ( type 4) filter. The filter is produced in the 1941 year, and then tested again and remarked in the 1943 year. Rare transitional completed Soviet ww2 gasmask.