milgard window balances

A quick learner from Seattle says:
I have a milgard single hung window that needs new balances and guides.
The opening part of the window is 29" high by 31" wide. I took the old balances out a while ago and can't find them now.
User submitted photos of a top sash guide.
Profile picture of Paul
Paul from SWISCO responded:
That top sash guide looks like our 18-166, though I cannot identify what your balance is. In the past, Milgard has used our Series 385 channel balance, but there is no guarantee that this is what you have. Do you have any old balances handy?
A quick learner from Seattle says:
Here are the Milgard balances I need. They are for 2 different windows and I need 2 of each.
First two: 26 2 IO CALDWELL
Second two: 20 3 KO CALDWELL

See the attached pictures.
User submitted photos of a window balance.
Profile picture of Paul
Paul from SWISCO responded:
Thank you. Yes, this is either our Series 380 or Series 385 channel balance. You will need to carefully measure your bottom nylon shoe to determine which is better (the size of the shoe is the only difference between them).
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