No markings. It's connected to the string
A home owner from Michigan says:
September 14, 2016
It's the white part that is attached to the string and the plastic pole goes into it. It's supposed to stay on top of the rod but it is broke so now the rod slides through it.
Tom from SWISCO responded:
September 19, 2016
I'm afraid the individual pieces of this balance cannot be replaced. Based on your damage, you will need a whole new balance. Now, there are a few different balances that could work, depending on your specific style, which I can't quite make out. You can see our possible matches here.