The number stamped on the balance is BF8 10#31 2-87 and also has the number 11600-17. Looking for replacement part number. Thanks.
Lauren from SWISCO responded:
November 1, 2023
Hello, thank you for posting,
Please review the 24-1033 Andersen sash balance that can be used to replace balance boxes marked with 10#31. Let us know if you have any additional questions!