• 5 Layer Filtration technology: filters are Made of activated carbon and non-woven melt-blown filter cloth, a five-layer filter system effectively keep away from a range of airborne contaminants, Dust, Haze, Allergies, Smoke, Pollution, Ash, Pollen, hazardous chemicals, heavy metal particles, etc.

• Made from 20% activated carbon, 40% melt-blown fabric, 40% non-woven Fabric

• Size of Adults Mask Filter: 12''x'8'cm Suit for adults mouth mask inside with filter slot.
• How to use: Insert the PM2.5 filter along the inside of the mask and use it, Refer to the second picture.
• Disposable supplies can't be reused or washed. Recommend replace filter once a week for the best effect or 3 day If there is serious contamination.

The first layer is non-woven fabric, the second layer is melt-blown fabric, the third layer is activated carbon, the fourth layer is melt-blown fabric, the fifth layer is non-woven fabric

When you breathe with the mask and filter, air passes through five layers before it reaches your lungs. Each layer has a different density in order to filter particles of different sizes. 

the 2.5 in PM2.5 refers to the size of the pollutant in micrometers. Bear with us here while it gets a bit mathematics-y! Micrometers have this symbol: µm and are equivalent to 0.001 millimeters. The smallest thing that the average human eye can perceive is about 0.1 millimeters, which is around the same width as a human hair. So in order for us to see something as incredibly small as a micrometer, we need to use powerful microscopes. Here’s a diagram to help you visualize the scale of these tiny particles.

So PM stands for particulate matter (also called particle pollution): the term for a mixture of solid particles and liquid droplets found in the air. Some particles, such as dust, dirt, soot, or smoke, are large or dark enough to be seen with the naked eye. Others are so small they can only be detected using an electron microscope.