Single hung window balances
A handy person from California says:
August 1, 2016
Part #punched into balance is 2730J,is this a balance you guys sale.
Tom from SWISCO responded:
August 3, 2016
Thanks for posting. Sounds like you have a 28" block & tackle balance with a stamp option of 2730. I'm afraid that's all I can tell based on your information, though. Now you just need to pick out the top and bottom fittings in order to determine the Series.
I recommend that you look at our Channel Balance Home Page and follow the steps in order to find the Series that best matches what you have.