1. First pull the headband loose every 2-4 cm, pass the mask headband with your hand, and the metal nose is forward.
2. Put on the mask and fit it closely to the face. Put the headband on the top of the mask behind your head, then pull the headband over your head, place it behind your neck, and adjust it to a comfortable position.
3. Use your fingertips along the metal bridge of the nose bridge, from the middle to both sides, and slowly press inward until it is close to the bridge of the nose.
4. Cover the mask with both hands and perform positive and negative pressure tests. (Positive pressure test: cover the mask with both hands and exhale vigorously. If the air overflows from the edge of the mask, it is improperly worn, you must adjust the headband and the bridge of the nose bridge again; The center will sink. If air enters from the edge of the mask, it will be worn improperly. The headband and the metal strip of the nose bridge must be adjusted again
