These filters are made to fit any of our masks and are sold in packages of 2.
PM2.5 filters are not equivalent to N95 masks. PM2.5 filters capture particles larger than 2.5 microns and add an extra layer of protection to your face mask.
Each of the PM2.5 filters are made of 5 layers of cloth, including two layers of meltblown cloth and one layer of activated carbon cloth to provide excellent filtration.
These filters can be used continuously for 16-24 hours, or for 1-2 weeks when used occasionally.