Usage Tips:Compatibility for Catit Fountain Filters - Our Fountain Filter is ONLY compatible with Catit Design Senses Fountain, Flower Fountain, Senses 2.0 And Fresh and Clear Stainless Steel (NOT Mini Fountain). Exellent Triple Filtration - The filters for cat water fountain is saturated filled with premium fiber cotton, activated carbon, and ion exchange resin, providing triple-action filtration to fully isolate pet hair and food residue, remove impurities and particle, filter heavy metals and odors, soften tap water and obtain clean and fresh water. Upgrading Structure and Encrypted Filter Cotton - Increase the filter holes and filter area to allow the water to filter faster and be fully filtered. Better filtration of impurities in the water, keeping the water clean and fresh. Improves your cat's health - By removing odors and impurities, reducing the risk of urinary tract infections, and softening minerals, these cat filters for water fountain provide clean and fresh water for your cat to drink, keeping them healthy and hydrated. Regular Replacement - In order to prevent the activated carbon dust fell into the water, please put the cat water fountain filter replacement soak in water for 5-10 minutes, and then thoroughly rinse under running water before using. Replace 1-2 weeks in summer, 2-4 weeks in winter. If have many cats in the use of fountain, you need to be replaced more frequently.