Hey there Evelyn! I figured I should ask you about something that's been troubling me with my brand new Gas Mask. It's a M65 Drager, however it's accompanied by a [ MS-4-172 / 92 P2 F ] Filter. It's definitely GOST, It's probably adjustable to the M65, however. Do you think it'd be safe to use?
I don't know for sure, but my personal preference is to avoid the use of bloc-manufactured GOST filters. Enough of the filters are known to contain asbestos, and they weren't exactly known for their safety record.