I am not sure of which shoe/bracket would go on this spiral balance but I believe I am searching for a S500 balance.
The window weight is 15.5lbs.
Length is 30in.
Bob from SWISCO responded:
January 27, 2020
Thanks for posting. See our S500-30 . If your window sash weighs exactly 15.5 lbs, a red tip option should work for you. The bracket you need should be our 17-012 ; just go over the dimensions to confirm.