Compatibility: The cat water fountain filters Compatible with 2.0L/67oz round stainless steel pet fountain. Please check the size and the model carefully before purchasing Multi-Layers Of Filtration: Activated carbon eliminates bad odors; ion exchange resin removes heavy metal ions and softens the water; non-woven fabric captures cat hair and impurities. Maximum protection for your pet's healthy drinking water Individual Packaging: Each fountain filter is individually sealed and packaged to ensure that each product is clean and protected from moisture Before Use: Please soak the filter in water for 5 minutes before use and rinse thoroughly under running waterv Replace The Filter Regularly: Please replace the cat water dispenser filter once in 2-4 weeks in summer and once in 4-6 weeks in winter to ensure clean drinking water. More frequent changes if more than one pet is using the water fountain Cat Water Fountain Filter, 4-Pack Pet Fountain Filter Replacement for 2.0L/67oz Automatic Pet Water Dispenser, Activated Carbon Filter for Stainless Steel 2.0L Automatic Circulating Pet Fountain