1Specially designed for Smartmi smart toilet, suitable for standard version, warm air version, washing and drying version, S, Pro and other models. 2premium PP filter cotton can effectively filter impurities above 5 microns, such as sediment, rust, insect eggs, red worms, suspended matter, impurity hair, etc. 3Comes with a special wrench, making replacing the filter cartridge as easy as twisting a bottle cap. 4Safe and environmentally friendly materials are selected, and the entire product has passed RoHS certification to protect the health of you and your family. 5The spiral model contains 3 filter cartridges. It is recommended to replace the inner cartridge every 6 months, so that you can use it with more confidence.