About this item Compatible Models Perfectly compatible with BB9-2 black purification elements and PF-2 fluoride replacement filter. Compatible with the Travel, Light, Big, Royal, Imperial, and Crown series Water Filter System High-Efficiency PurificationThe black filter is made of coconut-activated carbon and upgraded Fluoride Filters now uses both granular activated carbon and activated alumina as filter media. Effectively reducing chlorine, sediment, rust, VOCs, and other contaminants that may be harmful to health. (See the list of reduced contaminants under the product ) Longer use timeTo ensures your machine performance peak, we recommend replacing the fluoride filter every 1000 gallons per pair, replace the black filter every 6,000 gallons per pair, which will vary based on water conditions. Cost-EffectiveThe package includes 2*Black Water Filters and 2* Fluoride Filters, Works like originals, but half price, affordable replacement filter, save your money.