Window balance

Hello,

With this combination of attachments, you could have either the S380-35 or S385-35 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. 

The 34 5 stamp shown in your photo indicates that you would need 3450 spring strength options for your replacement balances to support a sash between 30-34 pounds. If your window sash weighs exactly 28 pounds, you may want to consider using 3440 options to support a sash weighing between 23-30 pounds. Thank you and let us know if you have any other questions or concerns.

Comparison of the S380 and S385 balance shoes.