20 4 KP CALDWELL

Hello,

We'd be happy to help but we would need to see the fittings attached to both ends of your channel balances to compare to our inventory. Keep in mind that the stamp code only indicates the spring tension needed to support the weight of the window, but does not identify the balance series. Thank you! 

Thanks for getting back to us. With this combination of attachments, you could have either the S380-21 or S385-21 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 2040 spring strength options for your replacement balances. Thank you and let us know if you have any other questions or concerns.

Comparison of the S378, S380 and S385 balance shoes.