replacement part for double hung window

Question

If you look at the attached pictures, I was able to purchase replacement clips, but I am unsure how to locate the second half which is the flat portion.

user submitted images of channel balance and attachments

Casey · Accepted Answer

In the photos you show a channel balance without a fitting and the others show SWISCO product code 19-002, Channel Balance Top Fitting.
I'm sorry I do not understand what "flat portion" you are looking for; please send a photo of that for us to research.