Alside double hung replacement window coil balances

A quick learner from Nashua, NH says:
Hi Swisco,

I recently had a horrible experience with Alside windows. Both coil balances on a double-hung replacement window had broken, causing the window to slam shut. Even with their "lifetime warranty", it took about 3 months(!) for them to send replacement coil balances. They also did not provide replacement instructions, but I figured it out eventually.

I'm trying to find out if you carry an equivalent in case we run into this problem again. I have attached a photo with horizontal and vertical dimensions shown adjacent to a ruler. The packing slip simple said "7 lb coil balances", without so much as a part number... Needless to say, I'm not too happy with Alside.

Hoping you can help since you seem to carry a wide assortment of parts. Thanks in advance!

User submitted a photo of a window balance.
Profile picture of Paul
Paul from SWISCO responded:
Hello, Scott! Hopefully we can help. Your pivot shoe resembles our 15-177, which leads us to recommend the Series 152 coil spring. Based on your packing slip, I would recommend the S152-7, but you may want to weigh your sash just to be sure. Two S152-7 springs can carry 7 pounds each on each side, which adds up to support for a 14 pound sash. If your sash isn't 14 pounds, let me know and we can try to work something out.
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