Broken channel balance

Hello,

I can't be sure since the balance shown in your photos is quite damaged but you can start by looking at the S770-28. I would recommend removing an intact balance from one of your windows to compare to the images below. 

If it's a match, you'll also need to weigh your sash to determine which strength option you'll need. There is a chart on the product page that explains how to choose your option based on the sash weight. Thanks for posting! 

Close up view of the Series 770 balance top.

Close up view of the Series 770 balance bottom.

The dimensions of the channel of the S770 window balance.