100 GPD Reverse Osmosis Membrane | Top Quality Replacement for any RO system This membrane fits most 4,5,6 and 7 stage residential RO systems with flow restrictions rated at 100 gallons per day. Length: 11.75" Outside Diameter: 1.8". Fits all standard 2" x 12" RO membrane housings. This membrane is top-quality, and equals or surpasses all of the performance specifications of the WATTS, Dow FilmTec and GE Osmonics membranes of the same 100 GPD capacity. This membrane is tested ANSI Standard 58 for material requirement. LiquaGen Reverse Osmosis Membranes are made of the highest quality spiral-wound Polyamide and offer outstanding contaminant rejection at water pressures up to 125 psi. Replace at 3-year intervals or sooner if TDS levels increase beyond normal levels This deliberate matching of design increases the efficiency and effectiveness of the contaminant rejection of the membrane along with optimizing the amount of reject water necessary to clean the membrane during normal everyday use.