1.Can be easily inserted into mouth mask.
2.The filter is suggested to replace once 15days for the best effect.
3.The filter is the must-have essentials to fresh the air of your breathing,
4.Powerful filter system consists of 5 layer filter material, effectively prevent pollutant like dust, small particle, PM2.5, fog from entering respiratory tract.
5.Filters air down to 1.0 micron to help to protect against most types of dust, pollen, mold spores, pet hair & dander, various bacterial allergens, and airborne effluents that can contain cold and flu germs.
6.Condition: 100% brand new.
7.One piece filter is for 15days.