The Berkey Authentic Black BB9-2 Water replacement Filters are designed specifically for the Berkey Water System, including models like Berkey Light, Big Berkey, and Imperial Berkey. These 2-stage carbon/charcoal filters are suitable for household use and are effective in removing bacteria from your water. Made of durable plastic and weighing 11.46 lbs, these filters are a reliable and efficient choice for maintaining clean and safe drinking water in your home. Get your Berkey water filtration system up and running with these authentic Berkey filters.