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. Most of the filters in the market are made of activated carbon. But these filters are made of high quality activated carbon, resin and cotton mesh. The water is deeply purified and safer. Features: 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). Dual-action filters: Resin and active carbon. Resin can soften water and reduce the chance of lithiasis. Activated carbon can adsorb impurities and odor, keep the water fresh and clean. Full grid filtering is more effective. 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