Compatibility: The replacement cat water fountain carbon filter is compatible with 1/2 gallon, 1 gallon, 2 gallon, Butterfly, Avalon, Pagoda, Seascape, Sedona, Seaside and Creekside pet water fountains; 【Three Layers of Filtration】: This replacement filter is made of a layer of cotton and activated carbon. It removes hair, debris, odors and other impurities, so your water always tastes fresh and clean; 【Pre-Filter Sponge】: The sponge can prevent debris from clogging and damaging the pump, extending its life; 【Replace the filter regularly】: 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, more frequent changes will be needed; 【WHAT YOU GET】: Includes 6 packs of replacement filters and 6 packs of foam.