This General Ecology RS-6SG cartridge element module is a replacement cartridge module for Seagull IV marine water purifiers. The high capacity, 23 LPM (6 US GPM) element module offers chemical free water purification against chemical, microbiological and aesthetic contaminants. The RS-6SG cartridge module has an nominal capacity of up to 23000 litres (6000 US gallons) before needing to be replaced, however this capacity does depend on the quality and hardness of the water. Seagull IV water purifier systems have been independently certified to meet the EPA Microbiological Guide Standard Protocol for removal of bacteria, cysts and viruses.