PM2.5 filter for the cloth mask (two pieces)

PM2.5 filter for the cloth mask, pack of two pieces, activated carbon face filter for air protection, consisting of five layers of protection: the first layer of membrane fabric filters dust at the micron level. the second layer filters industrial pollutants, car exhaust, and pollen allergens. the third layer of activated carbon fabric filters dust at the micron level. the fourth layer provides density for smaller particles. the fifth layer of membrane fabric filters all types of harmful substances. we recommend replacing the filter every week of use for the best effect.