Properly wearing a mask starts with hand washing. Before wearing a mask, wash your hands with flowing clean water for at least 20 seconds, preferably with reference to the 6-step washing method, and before wearing a mask, distinguish between the inside and outside of the mask. The dark side faces outward and the light side faces inward. And the location of the metal strip should be in the upper part near the bridge of the nose, first the mask flat spread hands push and pull the upper face, there is a nasal bridge tone in the upper, with the fingertips from the inside to press the nasal bridge strip, along the location of the nasal bridge strip to move to the sides to ensure that the mask airtight, the mask up and down completely spread all cover the mouth and nose.