These 3m 6800 Respirators Have A Secret Speech Diaphragm Built In
"those / these" are determiners and are used before nouns to refer to a particular group of things / people, e.g. these people / those rules / those buildings. Update: 题主问的是What are those? 然后他.
3M Universal Spectacle Kit 102 for Full Face Respirators 6700, 6800 and ...
