It's called PureFlow.
A few things sold me.
First, it's not just a straw. You can also use it to filter from bottles, too.
You can sip straight from the source. Or you can fill a water bottle full of dirty water and filter it from that, so you don’t have to be crouched down at a puddle or a stream if you want to get a drink.
It allows you to take that dirty water with you and drink it clean whenever/wherever you want.
Second, it filters down to 0.01 microns. That's finer than most straws you'll find on a shelf.
It removes 99.99% of the bacteria and protozoa that make water dangerous. The stuff that puts people in the hospital. E. coli. Giardia. Cryptosporidium. It catches microplastics too.
Now I'll be straight with you, the way I wish more of these brands were.
A filter is not a purifier.
PureFlow does not remove viruses. It doesn't pull out chemicals or heavy metals either.
For most grid-down situations, bacteria and parasites are the real threat, and that's exactly what this handles. If you want virus coverage on top of it, you pair it with purification tablets or a UV pen.
Anybody who tells you one little straw does everything is selling you a lie.
I trust PureFlow more because they told me what it doesn't do.