Replacement filter for cat fountain. Keep your cat’s drinking water is fresh, clean and safe. Helping you to take care of your cat’s health. The water is deeply purified and safer. Features: Value pack of 4 filters. Compatible with YOUTHINK, HOMMI, ISYOUNG, KOALAD, HAPPYPAPA, PEDY water fountain and other of the same size. Size: 5in(outer diameter), 1.5in(inner diameter). Activated carbon can adsorb impurities and odor, keep the water fresh and clean. PP cotton can filter out hair, sediment, and debris to clean water. Water quality can be removed by the three 3 types of filtration. The external cotton layer on each filter captures hair and debris. Three steps of filtration can assure the quality of the water and enhance the taste of freshwater for your cats. Rinse the filter with water thoroughly before using it, easy to mount it on the pet water fountain. In order to ensure the water clean, the filter should be replaced in time, please replace them within 2 to 4 weeks. Any problem,