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)