QUADRUPLE FILTRATION SYSTEM: Make pets happy with their drinks. This replacement filter consists of a cotton layer, activated carbon and ion exchange resin. it removes hair, debris, odors and other impurities so that the water always tastes fresh and clean. Sponges also prevent debris from clogging and damaging the pump,extending its working life;THOUGHTFUL SELECTION OF HIGH-QUALITY MATERIAL: Every drop of water is filtered through multiple layers. Provide your pet with oxygen-rich water that tastes better and makes your pet love drinking water. Let our beloved pets live more happily;WHAT YOU WILL GET: 8 packs of replacement filters and 8 packs of replacement pre-filter sponge.FRIENDLY REMINDER: Please soak the filter in water for 5 minutes before use and rinse thoroughly under running water. Replace the cat water dispenser filter once in 1-2 weeks in summer and once in 2-4 weeks in winter to ensure clean drinking water. More frequent changes if more than one pet is using the water fountain;