window Channel Balance

Hi there! 

With this combination of attachments, you could have either an 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 to remove and weigh your window sash to choose the appropriate spring strength option. There's a chart on the S380 and S385's product page that shows you which option you'll need based on the weight of your sash.

If you have any further questions just let us know. 

Comparison of the S380 and S385 balance shoes.