Grayl UltraPress Replacement Purifier Cartridge Water Treatment Accessories - Replacement purifier cartridges for the UltraPress are designed to last 300 cycles (40 gal. / 150L). 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. Removes waterborne pathogens (viruses, bacteria, protozoan cysts), including Rotavirus, Hepatitis A, Norovirus, Giardiasis, Cryptosporidium, E. Coli, Cholera, Salmonella, Dysentery and more Filters: particulates (sediment, microplastics) and many chemicals, pesticides, and heavy metals Improves taste, smell and clarity