The cat water fountain filter is compatible with PUPPY KITTY 2L ultra silent automatic water dispenser for cats and dogs. We recommend changing the filter every 2 4 weeks to keep the water frache and clean. 8 Pices filter defontaine water cat of high quality with cotonrsine and activated carbon. Filters hair and dbris, liminates odors and softens water, for a better got of water. To ensure that carbon dust does not occur, please rinse the water thoroughly before using the filter and provide clean water for cats and dogs.