Replacement filter for cat fountain. Keep your cat's water fresh, clean and healthy. Help you take care of your cat's health. Most filters on the market are made of activated carbon. But these filters are made of high-quality activated carbon, resin and nylon. The water is deeply purified and safer. Features: Pack and Size: Value pack of 2 filters. Compatible with PingPin fountain. Size: Diameter: 9.9cm / 3.9in; Thickness: 8mm / 0.31in. Dual action filters: Resin and activated carbon. Resin can soften the water and reduce the risk of stone disease. Activated carbon can absorb impurities and odors, keep the water fresh and clean. 3-layer filtration: Water quality can be improved with the 3 types of filtration. The outer nylon layer on each filter captures hair and debris. Three stages of filtration can ensure water quality and improve the taste of fresh water for your cats. Easy to use: rinse the filter with water before use, easy to mount on the pet fountain. To ensure the cleanliness of the water, the filter should be replaced in time, please replace it within 2-4 weeks.