Part Identification - Channel Balance having trouble with end options

I need to replace a bunch of window channel balances in my house. I have a bunch going bad at this point I am attempting to figure out end pieces as they are all identical and then I can start taking every window apart so I can figure out which ones need to be ordered. The current one I have pictures of is 1/2 inch wide, 27inches long, stamped with a 26-2 on it.