Usage Tips:[ MULTIPLE FILTRATION ] - The pet fountain filter replacement is saturated filled with premium activated carbon and and non-woven fabric, fully isolate cat hair and food residue, remove impurities and particles, filter heavy metals and odors, soften tap water and obtain clean and fresh water for your pets. [ PROTECT YOUR PET ] - This pet water fountain filter for cats inside is made of high-quality materials, safe and odorless. It plays an important role in improving water quality and protecting the health of pets' urinary system to keep your pet healthy. [ REGULAR REPLACEMENT ] - In order to ensure the health of your pets, please maintain the habit of changing the replacement filters for dog and cat water fountain every half month and the pre-filter foams every one month. Compatible with petsafe water fountain filters, compatible with drinkwell pet fountain parts, compatible with petsafe drinkwell replacement carbon filters, compatible with drink well replacement carbon filters. [ FOAM PRE-FILTER REPLACEMENT ] - Pack of 8; It can pre filter the particles in the water, protect the water pump from inhaling impurities, contribute to the optimal performance of the pump, and ensure long-term operation of the pump. pet cat filters for water fountain/water fountain filter for cats inside/cat fountain filter for drinking/pet water fountain filter for cats dog/cat feeding & watering supplies.