Usage and precautions: 1, Pay attention to the front and back of the mask. First of all, when we wear the mask, we need to pay attention to the front and back of the mask. When we wear the mask, don't wear the reverse, otherwise it won't filter the virus. 2, Don't touch the outside of the mask with your hands. After wearing the mask, be careful not to touch the outside of the mask with your hands, or your hands will touch the virus filtered outside 3, Disposable masks should not be recycled, because once used, masks can no longer be used to filter viruses. 4, Pay attention to the discard of masks. When we use the masks after use, we must pay attention to the process of discarding them. Don't discard them at will. We must throw them into the designated garbage can to avoid increasing the probability of virus infection. 5, Hold the metal strip on the bridge of the nose. When wearing the mask, you must hold the metal strip on the bridge of the nose with both hands, so that the mask is close to the nose and mouth, so that it can work. 6, Children under three years old are not recommended because of their low vital capacity.