double coil spring replacement

A quick learner from Ohio says:
Hi,

As you'll see on the photo, the bottom spring is broken. It reads: #9.0 35" P.

The spring above reads #7.5 35" 5232208.

I'm not sure which of your springs i.e. s159, s160 or s165 would be a replacement for the broken one. Or should I replace the entire balance? And while I'm at it, should I replace the balance on the other side of the window? It's a large vinyl tilt-in about 10 years old that gets a lot of use.

Thank you
Thumbnail of the uploaded file named window coil springs.jpg
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Tom from SWISCO responded:

Looking at your photo, your shoe looks like our 15-228 and your spring looks like either our Series 160 or Series 165. The Series 159 looks too big compared to yours, but that is ultimately the crux of it; you need to measure the thickness of your spring to confirm the better match. The Series 165 is 3/8" thick and the Series 160 is 1/2" thick. You just base your choice on how thick your original is.

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