The Pentair FreshPoint GRO75 is a genuine replacement reverse osmosis (RO) membrane for FreshPoint RO drinking water systems. The RO membrane is the heart of the system: it forces water through an ultra-fine semipermeable barrier to reduce dissolved solids and impurities, returning fresh, clean-tasting water to your faucet. This high-efficiency membrane produces up to 75 gallons per day, keeping the storage tank ready for on-demand filtered water. It is the correct RO membrane cartridge (GRO75-RC, part 655122-96) for the FreshPoint GRO-475B, GRO-475BP, and GRO-575B reverse osmosis systems, and installs with an effortless click-in change-out. Replace the RO membrane about every 18 months, along with fresh pre- and post-filters on your system's schedule; actual life depends on incoming water quality and usage. Note that overall system contaminant reduction and any certifications are properties of the complete FreshPoint system; see your system's data sheet for certified performance.