Window

Hello!

Take a look at our 15-177 pivot shoe, which uses the Series 152 coil springs, and compare our dimensions to yours to confirm this matches up to your original hardware. 

Are you referring to the coil weight? If so, look for a number stamped on your springs. If there aren't any numbers, you'll need to remove and weigh your window sash. Then, you'll divide the weight by the number of coils on both sides of the window to determine the correct strength option.