Help finding Spring balance

Thanks for posting. We may be able to help, but I cannot tell what the bottom shoe is. Can you remove the balance from the window and take a few pictures of the bottom shoe again? Thank you!

Perfect! I've narrowed this down to two possible channel balance Series: either our Series 380 or our Series 385.

Now, as you can see, the only difference between these two Series is their bottom shoe. The Series 380 uses the 15-005 while the Series 385 uses the 15-004. I can't quite tell what you have based on your pictures, though. Please carefully compare their dimensions to your own hardware and see which is a better match.