The only marking on the channel balance is UB 28C. The metal portion is 29" long and 1/2" wide. The balance shoe is 1" wide. The sash weighs 29lb. Attached are photos.
Tom from SWISCO responded:
October 12, 2022
Hello! If your shoe is 1", then our S380-29 would be my pick. This has the 15-005 1" deep shoe. Look it over and let me know if you had any questions!