Replacement Sash Questions

A quick learner from usa says:
I need to replace some channel balances, but I'm not sure what to order from you. The old balances are marked "26 4 IO CALDWELL". The window is a non-tilt sash window, the balance looks pretty similar to your 385 series.

The channel is 1/2" wide, the metal part of balance is 27" long. The top looks like your 19-005, but I cannot tell whether the bottom is 15-004 or 15-005; it looks like the depth measurement that differs between the two (1" or 1 3/32") measures 1.07" on mine, so I'm guessing the Series 385?

Also, the sash weighs 17.4lb, so for the "Sash Weight Range", should I choose the 2630 (13-19lb), or do I divide this by two and get 2610 because there are two balances, each taking half the weight of the sash?

Sorry to waste your time with such simple questions, but this is a first for me so I'm learning!
Profile picture of Tom
Tom from SWISCO responded:
Yes, the only difference between those balances is the size of the shoe. If yours is 1.07" I'd recommend the Series 385 as you suspected.

You do not divide the sash weight in half. If your sash is 17.4 pounds, you want the 2630.
How to Replace a Channel Balance Attachment
How to Replace a Channel Balance Attachment
VIDEO
WATCH >
Classifying Channel Balance Fittings
Classifying Channel Balance Fittings
GUIDE
READ >
Reply to Thread
Use this form to ask a follow-up question or to share your experience regarding this subject.
(your email address will be kept private and is only used to inform you when a response has been made)
Current wait time is 3-4 business days
We promise that one of our experts will personally get back to you as soon as they are able. Thank you very much for your patience and understanding. If your inquiry is time-sensitive, please feel free to reach us at (888) 991-1929 or at help@swisco.com.