Window balance replacement

Hello, thank you for posting,

With this combination of attachments, you could have either an S380 or S385 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. 

There should be a number stamped on the metal channel that will indicate the spring strength stamp option needed. If not, you will need to weigh the window sash and compare the weight to the strength chart on the product page to choose the correct stamp option.

Please review and let me know if you have any additional questions! 

Comparison of the S378, S380 and S385 balance shoes.