well, according to the official site the size of the pore of this filter is 0.2 micron which means this filter also can remove some organisms from Archaea Kingdom. but such a filter won't remove almost any viruses (these are 0.004 to 0.1 microns). A good thing is that it can be used for about 4000L of water, which is, honestly, unbelievable, I mean, is really great. and the price is good. might be very useful for travelers and some scientists. useful hunt, thanks )