Window Balance Help
If the depth of the bottom nylon shoe is 1-1/8", then this is indeed an S390-24. You'll need a stamp option of 2330. Let me know if you have any other questions.
Hello,
It looks like you have either our S351, with a 15-002 bottom attachment, or S390, with a 15-001 bottom attachment. Take a look at the image below to determine which balance you'll need. You'll also need a 2430 spring strength option for your replacement balances.
As for your question about the length, your 2430 stamp leads me to believe that this should be a 25" balance. It's possible that someone might have cut it down when they were repairing the window in the past, though I can't be sure why. I would recommend checking an identical window in the house to confirm the series and length. Also, make sure to only measure the metal channel, not including the end attachments. Thank you!
We actually just sent over a separate email with a custom order link and price quote for two 24.5" replacement balances. Take a look and please let us know if you have any other questions. Thank you!
