[Perfect Compatibility] Compatible with HAPUP cat and dog water fountain. Encourage your pet to drink more water and stay healthy. [Quadruple Filtration System] Each cat water fountain filter is composed of a separate foam pre-filter, high-density porous filter cotton, high-quality activated carbon, and ion exchange resin. Cotton layer: filters hair, sediment, and debris. Activated carbon: eliminates bacteria and chlorine odors. Ion exchange resin: softens tap water and helps prevent urinary tract diseases. Ideal for cat health! [Upgraded and More Sufficient Materials] The replacement blue and white cat water fountain filters are made of high-quality bulk filter material, which is non-toxic, visible, easy to use, and clean. Each fountain filter material is stored in an individual package and well reserved with the best effect! The filter element is fully upgraded, the quantity and quality improved to more effectively improve the cleaning ability. [Replacement Cycle] To help prevent