Series 350 1/2" Channel Balance

Question

I'm pretty sure I will need to replace a pair of old channel balances with the series 350, but cannot be sure of the "Sash Weight Range". The only identifying stamp on the channel is "27 4 1L CADWELL".
I'm going to guess I'll need the "2740", as my window falls into the 19-26 lbs range.
Please advise.
Thank you,
Tom

User submitted a photo of window hardware.

Paul · Accepted Answer

If your balance was originally stamped with 27 4, then the 2740 would be what I would recommend, as well. That said, the only way to confirm is to remove your sash from the window and weigh it on a scale to make sure it weighs between 19 and 26 pounds.