The use of electrostatic filter material, can effectively isolate the greater than 0.2m particulate pollutants, the dust filter efficiency of 0.5m can reach more than 95%.Effective filter dust in the , pollen, and other pollutants, protect the filter elements less pollution. It can effectively extend the life of the purifier filter more than 1 times, saving replacement costs.The pre filter screen used for the filter elements of the finished purifier can effectively increase the service life of the filter screen, so that your filter screen can truly reach the service life marked by the manufacturer.When the wind speed of 0.5m / s, wind resistance as low as 3.5pa, does not affect the wind speed.This filter is compatible with Mi purifier 1/2 / Plus, or cut it into the appropriate size for 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.White, soft, non-toxic, odorless, washable 1 or 2 times, remember not to rub hard.Range of use:Modified purifiers for household conditioners, fans, circulation fans, conditioners, exhaust fans, fans, etc.colour:whiteMaterial:cottonPackage Contents:4 * Filter cottonOnly 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.