The .01M UF replacement filter is included in the Well Water .01M Replacement Package for H2 Series. Best used on untreated, potable water, which includes well water. Eight stages of protection include: .01micron UF hollow fiber technology to reduce virus and bacteria, CaSO3 to reduce heavy metals and different forms of chlorine, and two stages of the highest quality carbon filtration. Rated for 500 Gallons. For use on the left side of your H2 Series water ionizer.