Generally speaking, masks are rarely used. Besides, it is attached to the mouth after all, and I feel more concerned about cleanliness. It is always strange for individuals to take it out of their bags and sell it ... If they want to buy it, they will usually go to regular stores, especially PM2.5 prevention, and some people will go to pharmacies to buy it.

PS: If you are a college student, and you are selling on campus, and your temperament and appearance are relatively approachable and trustworthy, then you may be able to sell some, depending on your luck.