My wife recently was discharged from the Army, and as she was throwing away a bunch of gear, I noticed these. I snagged them, and I feel that we, as a community, are better off as a result. There were two full sets. It looks as though the "smaller" nosepiece would accommodate an M-Frame lens, and take the place of the original nosepiece. I'll try it when I get home and let everyone know.

The smaller one is definitely for the M Frame, as that's a common SI component. The ESS range has a similar option too. However the gasmask insert is certainly a cool find. Thanks for the pics.