[Perfect Compatibility] Compatible with water fountain for cats and dogs. Encourage Your Pet To Drink More Water And Stay Healthy. [Quadruple Filtration System] Each cat water fountain filter is made of the separater foam pre-filter, high-density porous filter cotton layer of cotton, high quality activated carbon and an 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! [Improved and More Sufficient Materials]The blue and white replacement cat water fountain filters are made of high quality bulk filter material, non-toxic, visible, easy to use and clean. Each fountain filter material is stored in 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 charcoal dust from escaping. escape, please rinse the blue and white cat fountain filter thoroughly under running water before use, and soak it for ten minutes. Clean the blue and white HAPUP cat fountain filter weekly. We recommend replacing the filter every four weeks to keep the water clean. Please put the flat face up to ensure the best filtration!