Stamp option for Owens-Corning Window

Question

Please find attached 3 pictures of my broken Ownens-Corning channel balance. As you can see, it is 22" overall & I believe it is the Series 770. I have included a picture of the only stamp I could find on the channel. Could you help identify as to A,B etc?

User submitted photos of a window balance.

Paul · Accepted Answer

I'm not sure, "21TG" does not correspond to any Series 770 option. Your best bet is to weigh the sash and refer to the chart shown on the S770-22 store page.