1. Innovative technology: the use of electrostatic filter materials can effectively isolate particulate pollutants greater than 0.2μm in the air, and the dust filtration efficiency of 0.5μm can reach more than 95%. 2. Extend the service life of the filter: effectively filter dust, pollen, bacteria and other pollutants in the air, protect the filter elements to reduce pollution. It can effectively extend the life of the purifier filter by more than double, thereby saving replacement costs. 3. Improve service life: The pre-filter used in the filter elements of the finished product can effectively increase the service life of the original filter, so that your filter can truly reach the service life specified by the manufacturing trademark. 4. Low wind resistance design: When the wind speed is 0.5m / s, the wind resistance is as low as 3.5pa, which does not affect the wind speed. 5.Compatible: This filter is compatible with Xiaomi Mi Air Purifier 1/2 / Plus, or cut it to a size suitable for air conditioners, windows, electric fans. 1. Filter soot, PM2.5, etc. 2. Used in conjunction with the HEPA filter, placed on the front of the HEPA filter, can effectively extend the life of the HEPA filter. Soft, non-toxic, odorless, washable 1 or 2 times, remember not to rub hard. Range of use: Modified air purifiers for household air conditioners, fans, air circulation fans, air conditioners, exhaust fans, fans, etc. size: Can be cut into at least 2 pieces of your purifier filter, one piece can be used for about 1 month, and can be tailored as needed (one can be divided into two for an air conditioner hook.) Two areas can be used. Colour: white Material: cotton Size: 70x30cm Package Contents: 40 x filter cotton