Window channel spring replacement

Confirm that the metal channel length, not including the attachments at either end, is 28" exactly. If so, this looks like an S795-28 to me, with a stamp option of 28C. This is used for tilt windows, so I'd double-check the configuration of your window to be safe. See if your balance's bottom t-lock shoe matches the dimensions of the 15-195, the shoe that comes by default with this balance. Let me know if it differs at all. 

Finally, one difference between your old balance and our standard ones is that ours attach to the top of the window jamb with a screw-on tab, while yours has a hook like our 15-198. Can you show us a picture of the hole in the window that this hook attaches to? That will clue us in as to the best course of action here.

Great, thanks. That hole is square shaped, so what you can do is order our standard S795-28, along with a 26-200 Screw Plug. The Screw Plug can fit into that hole, allowing you to screw the standard balance to the window jamb. Let me know if you have any other questions.