Replacement filter for cat fountain. Keep your cat’s drinking water fresh, clean and safe. Help you take care of your cat’s health. Most of the filters on the market are made of activated carbon. But these filters are made of coconut shell activated carbon, ion exchange resin, high density non-woven fabric. The water is deeply purified and safer. Features: Dual action filters: ion exchange resin can soften water and reduce the risk of lithiasis. Activated coconut carbon can adsorb impurities and odors, keep water fresh and clean. The non-woven fabric can filter hair, sediment and debris to clean water. Nano filter barrier small particles and other impurities. Compatible with: Compatible with Veken, automatic flower fountain and others of the same size. Size: 4.9 inch (length), 1.38 inch (inner diameter), 0.31 inch (0.31 inch). Keep Animals Healthy: Loose filter material is more effective. Water quality can be eliminated by the 4 types of filtration. 4 stages of filtration can ensure