Replacement question

A home owner from Agoura Hills, CA says:
I have two windows that need channel balance replacements. The marking on the side says 2740 JJ. The length of the channel without the plastic ends is 28". I have two different angled pictures attached of both ends. Can you suggest which parts to order and if I need anything else to replace these parts. I will have handyman do the work.

Are they sold in sets of 2 or 1 piece? I assume I will need 4 channels for the 2 windows.

Thank you!
User submitted photos of a window balance.
Profile picture of Donna
Donna from SWISCO responded:
Thank you for posting! Just by eye-balling your pictures, I recommend that you take a look at our S390-28 channel balance with a 2740 stamp option. Does that look about right? Make sure to compare your sash weight with the weight rating for the 2740 option.
A home owner from Agoura Hills, CA says:
Thank you. Would it make sense to order the balances for a slightly higher sash weight perhaps the 2750 instead of the 2740? The builder put in the 2750 and it lasted about 10 years with very little usage of the windows. After about 10 years strings on 2 of the 4 balances broke. The windows also were hard to open and close all the way.
Profile picture of Tom
Tom from SWISCO responded:
2750 may work better, but it would depend on what the weight of your sash is. A stamp with a stronger weight rating than what your sash weight is could actually be harmful.
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)