Compatibility and pack details Cat fountain filter compatible with most 3L drinking fountains. Pack of 10 filters. The frequency of filter changes is lower than with conventional filters. Materials and filtration Made of activated carbon, ion exchange resin and nonwoven fabric. They filter hair and heavy metals and improve the taste of the water so pets drink clean and fresh water. Benefits for your pet Removes impurities and odors, helping to keep your cat's drinking water fresh, clean and safe. This supports healthier pets overall. How to use and size guidance Simply the carbon filter when you clean your pet's Water Fountain Filter. Please carefully check the size of the filter before the product. Use scenarios Scenario 1: You have a 3L cat fountain used daily by one or more cats; use these filters to maintain water quality with less frequent changes. Scenario 2: After cleaning or refilling the fountain, install a carbon filter to preserve water taste and safety. Scenario 3: In homes with tap water that has odors or metal content, these filters help reduce those elements, contributing to cleaner drinking water for your cat.