Jason:

The Frontier Pro pore size is 3.0 microns according to Cabela's product description (Aquamira itself is silent on this). Curious, where did you get your 2.0 micron info? Three micron is a pretty big pore size -- which is why we had our earlier discussion that the Frontier Pro should NOT be used alone -- but should be paired with chemicals -- like Micropur or Aqua Mira or bleach/chlorine.