These Advanced Ankle Systems Use Aerospace Grade Titanium
"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.
High-Strength Titanium Plate ASTM Gr1 Gr2 Gr2h Gr3 Medical Grade ...
