The SAFE filter has a built-in double filtration for high-quality, refreshing water for the health of your pet. Activated carbon removes impurities and odors with its powerful adsorption, so your pet can enjoy clean drinking water. PP cotton filters coarse dirt such as hair and sediment in the water. High efficiency and durability: One filter can be used for 2 to 3 weeks. However, to ensure your pet enjoys clean water, it is recommended to replace it every 2 weeks. This can purify the water more effectively, making it more refreshing, so your dog or cat can also enjoy delicious water. Easy to use: This ceramic filter is easy to install on the SAFE water dispenser. Note: Rinse the filter with water before use. Then clean the fine carbon powder that has formed during transportation to ensure it is clean and delicious. Your pet will love drinking water. High Precision: Thanks to its unique design, this filter provides the best water quality for your dog and cat. The activated carbon filter absorbs impurities and keeps your water dispenser as clean as new. You won't have to clean the water dispenser often, saving time and water. Wide Compatibility: This set contains 16 ceramic cat fountain filters, compatible exclusively with PetSafe Drinkwell, Avalon, Pagoda, Seascape, Sedona, and 8-gallon pet fountains.