Superior quality compatible reverse osmosis membrane for the Ametek WRO-3167 and WRO-31687 systems. Provides you with 24 gallons per day of healthy, great tasting fresh water. Maintains peak performance while helping to extend life of system. Manufactured in the United States. Usually should be changed every 2-3 years depending on your usage and water quality. If you need other filters for your system, our store has them in stock.