Help with identifying a channel balance

Question

Hey there, I have a milgard window from over 20 years ago. I haven't been able to find the part could use your help!

Half inch wide
21 inch long metal channel
Metal channel has "20 4 Caldwell HM"

I have a ton of pictures from the window and the channel I will upload.

Please and thank you!

Tom · Accepted Answer

Thanks for your photos. Based on what I see here, you have either our S351-21 or S390-21, depending on the depth of the bottom shoe. That's the only difference between them. I recommend measuring your shoe and referring to our dimensions to confirm the best match.

Comparison of the S351 and S390 balance shoes.