Fulfillment by Amazon (FBA) is a service we offer sellers that lets them store their products in Amazon's fulfillment centers, and we directly pack, ship, and provide customer service for these products. Something we hope you'll especially enjoy: FBA items qualify for FREE Shipping and Amazon Prime.If you're a seller, Fulfillment by Amazon can help you grow your business. Learn more about the program. APEC Water high capacity filter set is made in USA with high quality filtration components to provide a longer lasting filter set to protect and prolong the lifespan of your reverse osmosis system. Premium quality pre-filters and 4th stage ph+ calcium carbonate re-mineralization inline filter lasts 6-12 months for high performance contaminant removal and adds high purity food grade calcium minerals to enhance the water taste for people who prefer drinking mineral water. These standard size filters are 10" and feature ¼" quick-connect fittings for durable and easy filter change-outs. These filters are compatible with APEC Water System's counter top reverse osmosis drinking water system (RO-CTOP-PH & RO-CTOP-PHC ).All US made super high capacity filters1st stage: high-capacity 10" inline polypropylene sediment depth filter will effectively remove dirt, sand and sediment from the water.2nd stage: high capacity 10" inline coconut shell carbon filter to remove chlorine, tastes, odors, cloudiness and colors.3th stage: high rejection 90 GPD TFC reverse osmosis membrane. Removes a wide variety of contaminants including arsenic, chlorine, lead, fluoride, chromium, radium and more.4th stage: 100% US made high purity 10" inline calcium carbonate to effectively neutralize acidity.APEC Water Systems does not distribute or sell our products to any 3RD party sellers on Amazon. Please purchase genuine APEC Water Systems product in "new" condition from Amazon.Com or APEC Water Systems directly for authenticity.Manufacture warranty may not apply in all cases, depending on factors such as use of product, where the product was purchased, or whom you purchased the product from. Please review the warranty carefully and contact APEC Water Systems if you have any question.