Replacement balance coils for Milgard vinyl window

Hi there, Richard.

Thank you for reaching out to us. It looks like you'll need the 15-191 which uses the Series 160 coil springs. We also sell the compatible 15-150S single coil support. Take a look and let me know if you have any questions. 

You only need to replace what's broken so you can reuse the pivot shoes if they're in good shape. We just recommend you replace the springs on both sides of the window at the same time, even if only one side is broken. 

I also recommend you check the band of the spring for a stamped number. If they don't have one, you will need to divide the window sash by two to determine the proper spring weights.