This is not an individual part, it is an assembly.
Green and Yellow wires ID these as the protective earth ground. Short lengths of wire have lugs press fit in place and are bolted onto whatever those four terminals are. There is also a wire with lug on a screw right to the housing itself.
Agreed. Earthing distribution tie point. Notice that all the area is made of plastics. Such wiring is needed due to the extensive use of non conducting housing to provide safety grounding for outlets and other equipments.