You will receive a Free Christmas card as a gift for the Christmas Day! [Compatibility]: This replacement filters are ONLY compatible with 230oz 1.8GAL 7L Dog Water Fountain with 5 Layer Filter; [Four Layers Of Filtration Ensure That Every Drop Of Water Is Fresh]: Activated carbon eliminates bad odors; non-woven fabric captures cat hair and impurities; and sponge filters debris to prevent clogging and damage to pump. Maximum protection for your pet's healthy drinking water; [6Pack/12Pack Water Fountain Filter Replacement]: Included 6pcs/12pcs replacement filters, 6pcs/12pcs replacement pre-filter sponge and 6pcs/12pcs mesh-filters. Multi-effective filtration ensures that pets drink fresh water; [Frequency Of Replacement]: 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;