Yes and Tom is right and wrong.
Actually I did get a reply but he mis-understood what I was asking.
He tought I was asking about the rings when I asked about the circles.
But we did get some correct terminolgy.

"I think that they are talking about the sonic weld chips, they have a capture ring so they bond to the ring; and the electric weld chips does not require that ring because they are spot welded in the center of the coin."