Casey from SWISCO responded:
August 16, 2021
Hello, With this combination of attachments, you could have either an S380-31 or S385-31 channel balance. You’ll need to measure as shown below. The Series 380 has a 1" bottom attachment, and the Series 385 has a 1-3/32" attachment. You'll also need 3030 spring strength options for your replacement balances. Thank you and let us know if you have any other questions or concerns. Comparison of the S380 and S385 balance shoes.
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Casey from SWISCO responded:
August 16, 2021
In that case, I would recommend weighing the window sash on a common bathroom scale and following the chart under the balance product description to confirm the correct strength option for your window. |
Casey from SWISCO responded:
August 17, 2021
Then you'll need a 3040 strength option for your balances to support a sash weight between 23 and 28 lbs. |