Rainfresh 7300G is a self-disinfecting silver impregnated ceramic cartridge designed for use with Rainfresh and other gravity water filter systems. It traps and kills harmful bacteria > 99.9999% (E. coli, coliform, faecal coliform), traps protozoan cysts (Giardia, Cryptosporidium) and filters particulates as small as 0.3 microns (99.9%). The ceramic cartridge is cleanable and reusable until the cartridge gauge indicates a replacement is required. It’s a good solution for places facing water scarcity.