The FI-PHPLUS-QC is a 25cm inline filter that adds high purity food grade calcium minerals to enhance the water taste for people who prefer drinking mineral water.This mineral cartridge adds only 100% us-made high-purity calcium carbonate to effectively neutralise acidity and raise ph in the water.Other re-mineralization filter will claim to add various beneficial minerals back into the water; however, their mineral formulations are often from unknown sources.Please purchase genuine apec water system product in "new" condition from or apec water 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 if you have any question.