Shangqiu/Shangqiu sm3710 mask No.5 filter box set

It is made of silica gel and does not irritate the skin;
the breathing valve piece is not easy to pollute;
the visual field rate;
the headband can be adjusted into a hanging type, and the mask can be taken off and hung on the neck;
it is comfortable and durable to wear, and can be used together with filter boxes and glasses to prevent a variety of toxic gases.
size: medium , please