Hello there. This is a coil balance system. The coil springs regulate the window's movement, and so when they snap, the window can no longer stay open. I'm confident we can help, but I want you to remove the entire assembly, including the pivot shoe further down the jamb track that the coil springs connect to, and from which the window sash pivots inwards. The identity of the pivot shoe tells us the identity of the coil springs. We should be able to narrow this all down from there. See the guide on this page that explains how to remove and replace coil balance assemblies.
That is enough to make think you have an older version of the Series 140 Coil Balance system. For a system stamped '7' go with the S140-07 7 pound assembly. You will need to remove the window sash for replacement and installment--the video below shows how to do this for a similar coil spring assembly.
Yes, in the event the system doesn't work, you can return it. View our Return Policy here. Let us know if you have further questions.
