Help with replacement part

Thanks for posting. See our S385-27 channel balance, I believe this will work. You mention that your sash is 25 pounds, though. I believe your old balance has the incorrect spring strength. Your "26 5" stamp indicates that it's rated for sashes weighing 26 through 30 pounds, which is too strong. I would recommend our 2640 instead. You may want to double check the sash weight to make sure it's exact. This is a fairly important detail. It's important that you don't get a balance that's too strong or too weak. Think of it like Goldilock's porridge.