Navy Base Hurricane windows

Question

Hello, I need to replace the counterbalances in a window here on the Navy Base in Key West. Based on a conversation I had with your customer service rep. 63 is an odd sash weight stamp. There are two per side, which I guess is a bit odd also. I already took the window
Out myself and it was not more than around 30 lbs. I believe I narrowed down to a 390 series. I am looking for advice for the sash weight. I am unable to weight the sash currently,

Emily · Accepted Answer

Hello there!

Thank you for reaching out to us. It looks like you have either the S351-24 or S390-24 channel balance, depending on the depth of the bottom shoe. Measure as shown below to determine the best match.

I'm afraid the only way to determine the proper spring strength option is to weigh the window sash on the scale. I am sorry for any inconvenience.

Comparison of the S351 and S390 balance shoes.