Searching for 20 9 bw cmc 2

With this combination of attachments, you could have either an S380-21 or S385-21 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 and choose your spring strength option based on the chart under the description on the balance product page since your 20 9 stamp is from an outdated weight system.

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

Comparison of the S378, S380 and S385 balance shoes.