I bought a house that had aluminum windows with the 385 series channel balances. I got the replacement balances but then noticed that the guide sash was broken and the balances wouldn't stay in place..... This looks like the right guide sash but it says it's for the 370 series...Here's a picture of what was on the window but the top is broken
Paul from SWISCO responded:
January 28, 2020
Although your top sash guide is a little damaged, I think we can still help with this. Have a look at our 18-069 to start, and see if your measurements match up with ours.