防毒面具

shǒu cè shang shuō nǐ men yīng gāi dài shang fáng dú miàn jù

手册上说你们应该戴上防毒面具。

The manual says you should have your mask on.

shǒu shù yòng fáng dú miàn jù

手术用防毒面具

a surgical gas mask