Compatibility: These cat water fountain filters are compatible with Smartoo 152oz/4.5L wireless cat water fountain, helping pets enjoy a better drinking experience. Quadruple Filtration: The filter combines activated carbon, ion exchange resin, maifan stone, and non-woven fabric to effectively reduce odors, remove heavy metals, and soften water. Regular Replacement: For optimal performance, replace the filter every 2 to 4 weeks. If you have multiple pets, consider replacing it more frequently. Usage Instructions: Before use, soak the filter in water for 2 minutes and rinse thoroughly to ensure best results and provide clean, fresh water for your pet. Pump Care: If the pump does not operate properly, check for sufficient water level and remove any debris such as pet hair that may have entered the pump. Clean the pump as needed. Improved Water Taste: The filters help reduce chlorine taste and odor from tap water, making it more appealing to cats. Quantity Options: Available in 9-set or 18-set packs Color: As shown Material: Non-woven fabric Package Contents: Option A: 9 x Cat Water Fountain Filters, 9 x Sponge Foam Filters Option B: 18 x Cat Water Fountain Filters, 18 x Sponge Foam Filters Note: This package includes only the items listed above. Other accessories are not included. Note: Slight color variations may occur due to lighting and screen settings. Size measurements may vary by +/- 1-3 cm.