need new parts and not sure what to order

A home owner from Florida says:
April 8, 2021
We need some new balancer parts. I believe these are called "Block and Tackle". They measure 29" longt(he metal portion) and are 1/2" in width. Can you please let me know if you carry a replacement part? We need 10 of these.
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Casey from SWISCO responded:
April 13, 2021

Hello,

With this combination of attachments, you could have either an S380-29 or S385-29 channel balance. You’ll need to measure as shown below. The Series 380 has a 1" bottom attachment, and the Series 385 has a 1-3/32" attachment. You'll also need 2820 spring strength options for your replacement balances.

Thank you and let us know if you have any other questions or concerns.



Comparison of the S380 and S385 balance shoes.
Comparison of the S380 and S385 balance shoes.
A home owner from Florida says:
April 13, 2021
Thanks so much for your response. I measured and will need the S380 with the 15-005. Can you elaborate on the 2820 spring strength options? I'm not sure what this is or how to find out what I might need.
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Casey from SWISCO responded:
April 13, 2021

Sure, the 28B stamp shown in your photo correlates to a 2820 strength option shown on the S380-29 product page, which means that the balance spring will support a window sash between 12 and 16 lbs. 
29" Series 380 Channel Balance
29" Series 380 Channel Balance
S380-29
$11.10
29" Series 385 Channel Balance
29" Series 385 Channel Balance
S385-29
$11.10
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