The first step is to check whether the mask is damaged. If it is damaged, it must be replaced in time.

In the second step, when wearing, two ropes need to be passed around the head in sequence, the first rope is downward in the back of the head and the second rope is upward in the head.

The third step is to press your finger against the nostril, match the mask to the model of the bridge of the nose, and make it fit perfectly.

The fourth step is to cover your hands with your hands on both sides of the mask, and then breathing can obviously feel the mask changing in size.

Step 5 If you feel obvious difficulty in breathing or the resistance becomes greater while breathing, then you must change one.