The Systems IV SteamTech ST1/ST2 Steam Cooker Carbon Filter Cartridges 2-Pack is a set of white and red carbon filter cartridges designed specifically for the Systems IV SteamTech models ST1 and ST2. These cartridges are made of plastic and metal, with a filtration method of carbon/charcoal to effectively remove chlorine taste and odor. With a cartridge life of 6 months, this 2-pack is suitable for use in steam cookers to ensure clean and safe cooking water.