1. Sealability, PM2.5 is a fine particle. Its size is 2.5 microns, which is equivalent to one tenth of the hair diameter. Therefore, if the sealability is not up to standard, PM2.5 will enter the market.

2. Filterability, ordinary mask.

3. Comfort, which is commonly referred to as breathing resistance, and prolonged wearing of a mask can easily cause people to feel stuffy and cause hypoxia.