replacement block and tackle tensioners

A handy person from residential says:
I am replacing the broken balancers in my windows. They look like the 350 series. They are 29 inches long. They have stamped on them ub 26D USB and 28D USB. I was wanting to order the correct one. Thanks Jim
+
User submitted picture of channel balances.
Profile picture of Paul
Paul from SWISCO responded:
Thank you for posting, and for the pictures. Are these two balances both in different windows, or are they a single pair in a single window?
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 4-7 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 856-317-6263 or at help@swisco.com.