Pentair Omnifilter Easy Flow Us1 Replacement Filter Keep fresher, better-tasting water flowing with a replacement filter for the Pentair OMNIFilter Easy Flow US1 system. Replacing the filter is easier than ever with a quick-change, click-in design. Get better water with reduced chlorine taste and odor (NSF 42 certified). To change the filter, simply flip the filter cover open, pull out the old filter, click the new one in, and snap the cover closed Easily change the filter without turning off the water thanks to a built-in check valve system Long filter life of 6 months or 5,000 gallons means minimal maintenance Enjoy better-tasting water with reduced chlorine taste and odor (NSF 42 certified)