Need parts
Hello,
With this combination of attachments, you could have either the S380-27 or S385-27 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You'll also need to weigh your sash to determine which option you'll need for the 26 9 stamp balances, which is from an outdated weight system. There is a chart on the product page that explains how to choose your option based on the sash weight.
The 26 5 stamp balance will require 2650 strength options to support a sash between 26 to 30 lbs. Thank you and let us know if you have any other questions or concerns.