The Grayl UltraPress Purifier Cartridge is a replacement cartridge for the Grayl UltraPress (product 1025010533). Lifespan will decline when purifying water with high levels of silt, sediment or tannins. Cartridge press time increases towards the end of the cartridge lifespan; when press time reaches 25-30 seconds, the cartridge should be replaced. Cartridge continues to protect, even as press time increases.FeaturesRemoves waterborne pathogensImproves taste, smell, and clarityBPA-Free Materials