US windows Factory / Coil Balance

I'm sorry, but I don't recognize this Series coil balance. I will need some additional information before we can research a replacement.

First, please remove the window sash and take a photo of the pivot lock shoe. In your pictures above, the sash is obscuring important details. I will also need to know the width and thickness of the pivot shoe. These dimensions are essential! Please also take a photo of the bottom pivot bar on the sash. Finally, how is the spring attached to the shoe, and what is the width of the spring?

Thank you. For the coil springs, I recommend that you consider our S152-9. This can work for sashes weighing from 17 through 19 pounds. As for the pivot shoe, see if our 15-177 is a good match. The most important dimensions are the width and thickness, so you should triple check those to make sure it matches.