Please help identifying the correct part number

Question

Hi. The pictures I have attached are for two windows. The length of the balance is 29 inches are there is a number stamped on the side. It is hard to read, but I believe it says 28C USB.  I have ordered from you before and have had great success. Thank you so much!

Casey · Accepted Answer

Hello,

With this combination of attachments, you could have either the S380-29 or S385-29 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 2820 spring strength options to replace your 28B balances. You would need 2830 options for your other balances if you're confident that the stamp is 28C. If you want to be positive, you can also weigh your sash and follow the chart on the balance 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.