So I recently bought a east german issue MM-1 gas mask from ebay. The mask is nothing special, except that it's from the first batch of MM-1's made in moskow, but that's not the point, the point is the filter. I know that the filter normaly issued with this kit is the E0-16 filter, but mine came with one that looked like a E0-14 filter. I originaly though it was a E0-14 filter and the seller just mixed it up, but the labeling on the filter suggests that it ins't a E0-14 filter. It doesn't say E0-14 anywhere but instead it says " бсс-М0-4у " on it. For the date it says " III-62-14 " which I think means it was made in march of 1962. Under that it also says " Г 0230" . It also has 2 cyrillic letters on the bottom which I can identify due to wear. Finally there is a stamp on the bottom of the front side of the filter that says " 830 " and a sharpy mark on the cap that says " 15 " . I have no clue if this is just misslabeled or something else, I am also wondering why it was included in an east german kit, since the seller doesn't have any other masks and filters for sale and this smells like it has been sitting in his basement since the fall of the berlin wall ( the seller shipps from a village close to berlin ). Help would be appreciated and if you also have no clue what this is then I am sorry for wasting your time.