Features:Value pack of 4 filters.Compatible with YOUTHINK HOMMI ISYOUNG KOALAD HAPPYPAPA PEDY DADYPET automatic flower fountain and other of the same size. Size: 5in(outer diameter) 1.5in(inner diameter).The filter is made of resin and activated carbon to help remove chlorine odor and organic pollutants from the water.To improve the water quality three kinds of filtration (resin charcoal filter cotton fabric) can be used to remove impurities and debris from the outer polyester layer of each filter.The three steps of filtration can ensure the quality of your cat and improve the taste of your cat. It can last for 3-4 weeks to reach the standard water quality. We suggest that you change it in time to provide healthy water for your cat and dog and improve the water quality.3-layer filtration system filtration deodorization purification: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 qualityThe third layer of PP cotton to remove odor and improve taste:Inner and outer filter cotton:Specification:Name: Cat water fountain filterInside material: Activated carbon resinSize: Outer diameter:127mm/5in inner diameter:38mm/1.5in thickness:8mm/0.31inPackage size: 13.2 * 6 * 13cm/ 5.20 * 2.36 * 5.12inPackage weight: 65gGift Box PackagingPackage List:4* Cat water fountain filter