The Xiaomi Smart Pet Fountain Filter Set is a great way to breathe new life into the Xiaomi Smart Pet Fountain. The filter set consists of everything you need to maintain your pet fountain including two main filters, two pre-filter units and a water pipe. The four-stage efficient deep filtration system can purify impurities such as fine particles, hair and residual chlorine, as well as Ca or Mg ions that cause kidney stones. These are effectively intercepted and filtered, ensuring healthy, tasty water that pets will love to drink.