Help identifying correct replacement part

Question

Hello,I need to replace both counter weight guides for a window. The measurement of the metal track is 30". I have attached pictures for identification. I was not able to find the v notched top guide on your site.

Jasmine · Accepted Answer

Thanks for your post! This window balance can be replaced with either the S351-30 or the S390-30. To determine which of these is the correct series for the repair, you'll need to confirm the depth of the bottom shoe.

You'll need to look for a stamp/marking on the back of the channel to determine the correct option to select.

Comparison of the S351 and S390 balance shoes.