1. Innovative technology: the use of electrostatic filter materials can effectively isolate particulate pollutants greater than 0.2m in the air, and the dust filtration efficiency of 0.5m 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 filters 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 filters of the finished product can effectively increase the service life of the 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 Mi Air Purifier 1/2 / Plus, or cut it to a size suitable for air conditioners, windows, electric fans. colour:White Material:fiber size:30 x 72cm Package Contents: 20 x Electrostatic Filter Cotton Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.