Not sure what part to order

With this combination of attachments, you could have either a S380-30 or S385-30 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 find the stamp on the back of the metal channel or weigh your sash to determine the spring strength 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 the S378, S380 and S385 balance shoes.