I don't know where this thing is used in fishing gear. You'd better give me a map of where it is used.
Chain link, the upper ring is the fishing line (main line), the lower hook is hung with the black apron on the right side, and then the hook auxiliary line is hung on the apron.
The middle part is covered with lead.
This thing is to combine the eight-character ring with the lead seat.
There are people above who say that the one on the right is lead, and I don't know how to mislead people.