【Wide Compatibility】- The size of the fountain filter is 4.96 x 4.96 x 0.35 inches, and the diameter of the center circle is 1.5 inches. Suitable for most 1.6/2/2.5L cat fountains. Please measure your fountain and check before ordering whether the filter can be installed in your fountain. 【Triple Action Filter】- Cat Water Fountain Filter use non-woven fabrics, activated carbon and natural resins to effectively purify water, filter harmful substances in water, and provide pure water for cats. 【Easy to Use】- Replacement Filters for Cat Dog Just put on the side raised down and flat side up, you can install it easily. 【Recommendations】 - Flower Fountain Cat Filters - Please soak in clean water for 2 minutes and rinse before use, replace every 2-4 weeks to ensure the best protective filtration for our pets. 【Value Filter Set】- 8 x Cat Water Fountain Filter, helps pet to increase water intake and reduce the risk of urinary tract infections."