Window Coil replacement part, on the coil it has the number 7, these are for double hung windows.

I believe I can help you with this. The manufacturer discontinued your balance system and it replaced with the Series 150 coil springs and the 15-140 pivot shoe. Since your balance is marked with a "7", our S150-7 should work. The other parts are the same: the 15-143 coil bushing, 15-144 coil bushing cap and 15-145 support barrel. Take a good look at each part and let us know if any other questions come up. 

Each piece is sold separately and will need to be assembled.