Features: Value pack of 4 filters. Compatible with YOUTHINK, HOMMI, ISYOUNG, KOALAD, HAPPYPAPA, PEDY, DADYPET, automatic flower fountain and others of the same size. Size: 5 inch (outside diameter), 1.5 inch (inside diameter). The filter is made of resin and activated carbon to help remove chlorine, odors and organic pollutants from the air. water. To improve water quality, three types of filtration (resin, charcoal, filter cotton cloth) can be used to remove impurities and debris from the polyester outer layer of each filter. The three stages of filtration help ensure your cat’s quality and improve your cat’s taste. It may take 3-4 weeks to reach standard water quality. We suggest you change it in time to provide healthy water for your cat and dog and improve water quality. 3-fold filtration deodorization purification layers The first layer of PPF cotton microporous filter hair food debris: The second layer of activated carbon is used to remove scale and purify water quality< br/>