This Cat Water Fountain Filter Pack is specifically designed for the HHOLove brand of cat fountains with a 23oz/1.6L capacity and is not compatible with other brands. Make sure to verify your water fountain's filter model before purchasing. Each pack includes three filters measuring 13713738mm, and there is also an option to purchase in bulk with a box containing 36 packs for a total of 108 filters. The filter features a quadruple filtration system consisting of high-density polypropylene (PP) cotton, premium coconut shell activated carbon, high-density microporous filter cotton, and ion exchange resin cores for efficient purification. For optimal performance, filters should be soaked in water or rinsed before use and replaced every 2-4 weeks to remove impurities such as dirt and cat hair, ensuring clean water for your pet.