Moderate to severe cardiopulmonary diseases, hypertension, claustrophobia, anxiety reactions, patients with a history of spontaneous pneumothorax, or those with chest tightness and dyspnea, etc. Please do not wear masks, which may be dangerous. When you have such a mask in your health, dont give it away to relatives and friends who may have these diseases.

If the air is too dirty to wear, please consult a professional doctor who understands your physical condition first (note: not all doctors know about various masks; you can first try to ask him what is a N95 mask).

Pregnant women, infants, and frail elderly should try to avoid wearing masks.

If wearing, if you feel dizziness, nausea and any other discomfort during use, remove it immediately; consult your doctor before wearing.

If it is not used to prevent haze, qualified gauze masks and ordinary medical masks have relatively low exhalation resistance, you can consider.