They are real short on details.
They did mention a 2 micron pore size, which is really bad. For comparison the larger Sawyer is .1 and the small one is .02.
However, they do mention that they have a special silver something or other that kills bacteria on contact and they don't mention at all at about virus contamination.
If you look at their charts, you see that the worst places they have NR for and tell you not to drink the water there.
They also have this in capital bold letters.
WARNING : DO NOT USE ÖKO FILTERS WITH MICROBIOLOGICALLY TAINTED WATER OR WATER FROM UNKNOWN SOURCES
So yea, I will be sticking with my Sawyer.
Too bad though, who ever comes up with a water filter that weighs less than 8 oz, filters/kills protozoa, bacteria, viruses and filters out chemicals will be rich.