CompatibilityRplacement filters & pre-filter sponges set, perfectly compatible with 95oz and 67oz automatic pet water fountain; We provide 12-Month Replacement and 24-hour customer service, please contact us if you have any question. Triple Filtration SystemCat water fountain filters has 3 layer filtration system, high density cotton non-woven fabric layer fliter hairs and residue, keep water clean; Activated carbon layer can remove chlorine and odor, purify and freshen water; Ion exchange resin, can filter heavy metals and improve the taste, which can leading pets to drink more water, and reduce the risk of urinary tract infections. Pre-Filter Pump Sponges High density pre-filter pump sponges replacement, can capture hair and debris, and prevent them from entering into the water pump, extend the life time of your fountain pump. Replace RegularlySuggest replacing cat fountain filters and sponges every 4 weeks, please change it more often if your water fountain serve for multiple pets. Warm TipsBefore replacing the filter, please soak the filter in water for 2 minutes and then rinse filter thoroughly with running water, which will prevent carbon dust from shedding into water, keep water clean and fresh.