Two Pack (200 Gallons total) of plug n play in-line filtration replacement cartridges for the GEIGERRIG in-line VIRUS filter. The VIRUS Filter from Geigerrig provides high flows and long service life in the most compact, lightweight cartridge available today. Tested and certified to remove: Greater than 99.9% Protozoans (Cryptosporidium and Giardia), Greater than 99.9999% Bacteria (Raoutella terrigena), Greater than 99.99% Virus (MS-2 Bacteriophage). Meets or exceeds ANSI / NSF Standard 53 for removal of Protozoan cysts, Bacteria, and Virus. Testing performed by independent, accredited laboratory; DOD, NELEAC (ISO-17025), FL DOH Laboratory #E82924, EPA# FL01147.