Anderson sash balance

It's hard to tell what you have based on this information. The best way to determine an Andersen balance replacement is to show us the stamps printed on the balance box itself. If that is not possible, we will need the height and width of the visible glass for both the upper and lower sash, however this is not the most reliable method.

I'm afraid that number does not tell us what you have. Please look over Paul's response from the 4th. The two methods he mentioned are the only ways we can determine what you need.

Thank you for the glass dimensions. Based on these measurements, I recommend our 24-837 Andersen sash balance.

Yes! We recommend replacing both balances at the same time. This will make sure both balances work optimally; when you have an old balance and new balance working in tandem, the new balance tends to wear out sooner than it ordinarily would since it has to make up for the old balance's slack. If one of your old balances is still operable, you can always keep it aside as an emergency backup.