Compatibility: The replacement carbon filter for cat fountain is compatible with 1/2 gallon, 1 gallon, 2 gallon, Butterfly, Avalon, Pagoda, Seascape, Sedona, Seaside and Creekside pet fountains; 【Three-layer filtration】: This replacement filter consists of a layer of cotton and activated carbon. It removes hair, debris, odors and other impurities so that the water always tastes fresh and clean; 【Pre-filter sponge】: The sponge can prevent debris from clogging and damaging the pump, thus extending its service life; 【Replace the filter regularly】: Please soak the filter in water for 5 minutes before use and rinse thoroughly with running water. Replace the cat water dispenser filter every 4 weeks in summer and every 4-6 weeks in winter to ensure clean drinking water. If multiple pets use the fountain, changes will be more frequent; 【WHAT YOU GET】: Includes 6 packs of replacement filters and 6 packs of foam.