channel window balance 1900 bsi

With this combination of attachments, you could have either a S380 or S385 channel balance. You 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 weigh your sash to determine which option you'll need. There is a chart on the product page that explains how to choose your option based on the sash weight.

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

Comparison of 15-004 and 15-005