Replacement filter for cat fountain. Provide your cat with fresh, clean and safe drinking water. Helps you take care of your cat’s health. Made from high quality activated carbon, resin and cotton mesh. The water is deeply purified and safer. Features: Compatible with Youthink, Hommi, ISYOung, Koalad, Happypapa, Pedy and others of the same size. Size: 5" (outer diameter), 1.5" (inner diameter) Double action filter: resin and activated carbon. The resin can soften the water and reduce the risk of stones. Activated carbon can adsorb impurities and odors, keep water fresh and purify. Water quality can be eliminated by the three 3 types of filtration. The outer cotton layer of each filter captures hair and debris. Three stages of filtration can ensure water quality and improve the taste of soft water for your cats. Before use, rinse the filter thoroughly with water, easy to mount on the pet water fountain. In order to ensure clean water, the filter should be replaced in time. Please