[Package Contents]: 8-pack of cat fountain filters, individually wrapped, hygienic and clean, for more protection for your pet. [Triple-Effect Filter]: Triple-effect filters use non-woven fabrics, activated carbon, and natural resins to effectively purify the water. The outer cotton mesh of each filter traps debris. Guarantees pure cat water. [Instructions for Use]: Soak the cat fountain filter thoroughly in water before use and then carefully connect it to the water dispenser. To ensure clean water, the filter should be replaced in a timely manner: 1-2 weeks in summer and 2-4 weeks in winter.