Channel balances needed

A home owner from Frederick MD says:
They are 31" in length.

I will need several.

They are marked "30 3 BO CALDWELL"

I don't have installed photos. This one kinda fell down and I pulled it out.
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Bob from SWISCO responded:

Thanks for posting. See either our S380-31 or S385-31 Channel Balances. The only difference between these two Series is the 'depth' of the bottom nylon shoe. With the Series 380 the depth of this nylon shoe is 1", whereas with the Series 385 it is 1-3/32". Compare with your own and see what is best.

Once you know what balance to pick, you must select a stamp option. Your stamp code of 30 3 conforms to our stamp option of 3030, which is for a window sash in the weight range of 16 through 23 lbs.

A home owner from Frederick MD says:
Thanks!

I measured the depth and it's 15/16"

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Bob from SWISCO responded:

Sounds like the S380-31 should work for you then!

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