Up/Down Window Channel Balance

A home owner says:
December 21, 2015
Aluminimum frame, spring, nylon thread control mechanism. I browsed your site for the the part, but could not find it. Attaching couple of images related to the part for you to help me buy the part.

Thanks
Sanjeev
User submitted photos of a window balance.
Profile picture of Tom
Tom from SWISCO responded:
December 22, 2015
Based on these pictures, I believe you have either our S380-27 or S385-27, depending on the size of your shoe. The shoe size is the only difference between these two balances, so you will need to measure yours to confirm.
A home owner says:
December 26, 2015
After I measured the shoe size, it looks like S385-27 is the right part for me. But, how do I pick the sash weight option ? Attaching a picture of my window for you to suggest the appropriate sash weight option I need to pick.

Thanks
Sanjeev
User submitted a photo of window hardware.
Profile picture of Tom
Tom from SWISCO responded:
December 29, 2015
I'm afraid seeing the window doesn't tell us what option you need. Your stamp does, though. Since you have "26 4" stamped on your balance, our 2640 option should be what you need. If you want to be 100% sure, you can always weigh your sash on a scale and refer to the chart we have on the S385-27 store page.
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