Hello, I apologize for not being as active as I used to be. But recently I’ve been writing a large essay on Wartime issued Soviet filters, but there is a lack of good info on the filters. I am surprised that such a important subject in Soviet PPE history is missing. I’ve also seen a surge of incorrect information about pre 1945 filters. One of my favorite threads on here is dimas thread on the same subject. However most of the info in the article is vague or incorrect. So I’m setting out on a journey to find the correct information on the filters. I will post the article here once I complete it and I’m 100% sure the information is correct. Regards Raul