[High-Efficiency Filtration] – This water filter elements set is a replacement for gravity filtration system filters. It has passed high-standard testing by authoritative institutions and efficiently reduces chlorine, fluoride, heavy metals, taste and odor, sediment, large particles, and other harmful substances. Clean and healthy water can be enjoyed outdoors at any time. [BB9-2 Black Filter] – The BB9-2 black filter is made from high-grade materials. Compared with ordinary granular activated carbon, it has higher adsorption capacity and efficiently reduces fluoride, chlorine, and impurities. [PF-2 Fluoride Filter] – The PF-2 fluoride and arsenic reduction filter elements adsorb fluoride, arsenic(V), pre-oxidized arsenic(III), and other residual common heavy metal ions. [Perfect Compatibility] – This set of filter elements is compatible with Berkey gravity filtration system filters and fits FOR Doulton Super Sterasyl, Traveler, Nomad, Royal, King, Big, Imperial, and Crown series. It is recommended to replace the PF-2 water filter every 1,000 gallons and the BB9-2 black filter every 6,000 gallons for optimal performance, or based on water conditions. Material: Plastic Color: White + Black Package Contents: 2 x BB9-2 Water Filters 2 x PF-2 Water Filters Note: Light reflection and different display settings may cause slight color variations between the item and the image. A measurement error of +/- 1–3 cm may occur due to manual measuring.