I was looking at US Cav's website, and I ran into these critters:

Survival water filter
Mobile water filter

They've got NSNs so they've theoretically passed testing at Natick, but I've never seen these before. Being that little and that light, even if they are only good for 100L, they could go into a vest packaged kit or a butt pack with a minimum of bulk. It sounds like first one was made for like aircrew kits or larger SERE kits.

Anyone worked with these or heard anything about them?