Not much info on the purelator type inline filters. I do have a replacement element but there was no info on the packaging. I did look at it with 14X magnification. It looks very much like nylon mesh fabric as the filtering medium. A rough estimate - the pore size is pretty close to a couple of strands of hair width. I used my wife's hair as I couldn't find any of my own I could spare. Then I thought of something else. I scanned the filter at 1000 dpi and it looks like the pore size is something like .003 inches based on three pixels per. For my airplane, I don't worry about ethanol and the filter element or water, for that matter.
Lowell