25ds336

Thanks for writing in! Since your existing balances both have a stamp with a 25 at the beginning of the number, and both have winged top guides and bottom shoes, the replacement balances you'll need are either the S380-26 with a 1" shoe or the S385-26 with a 1-3/32" shoe. These are 26" balances.

To confirm the correct series, you'll need to confirm the dimension for the depth of your bottom shoe.

Comparison of the S380 and S385 balance shoes.

Given the 25DS36 stamp on the balance in the right side of your window, I believe you may have a sash weighing 36lbs so you should be able to use the 2570 stamp to replace your balances. However, I would strongly suggest double checking the weight of your sash to confirm this. If your sash does weigh more than 36lbs, your balances will need to be a custom assembly.

The balance you purchased is the S350-36. This is a 36" channel balance and has a wingless top and winged bottom shoe. You may submit the request for your return here.