Compatibility: The cat water fountain filters are compatible with for Smartoo 152oz/4.5L wireless cat water fountain. Let pets always get the best drinking experience. Quadruple Filtration: The filter uses activated carbon, ion exchange resin, maifanstone and non-woven fabric to effectively eliminate odors, remove heavy metals, and soften water. Regular Replacement: To maintain the filtration effect, it is recommended to replace the filter every 2-4 weeks. If you have multiple pets, please consider shortening your replacement cycle. Warm Tips: Please immerse the filter in water for 2 minutes and rinse thoroughly before use to achieve the best filtration effect and ensure your pet enjoys clean and fresh water. Important Notes: If the pump malfunctions, it may be due to low water level or pet hair debris entering the pump. Please ensure there is enough water or clean the pump promptly. Improved Taste: filters reduce the taste and odor of chlorine found in tap water, which can make the water more appealing to cats. Quantity:A:9 Set/B:18 Set Colour:As Shown Material:non-woven fabric Package Contents: 9 * Cat Water Fountain Filters 9 * Sponges Foam Filters / 18 * Cat Water Fountain Filters 18 * Sponges Foam Filters Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.