Sash balance spring

Hello, one of my sash balance springs in my bedroom window broke, and I need a new one. I previously bought pivot pins from you which worked great! This is the part that mates with that pivot pin, although the pin I replaced was on a different window.
I'm interested in buying a small number of these springs, one to rock and one (or a few) to stock, as they say. Depends on how much they cost. I'm sure I'll break another one sometime in the next 20 years.
Thanks in advance!

Awesome, thanks alot Emily! That looks exactly like it.