Window coul balance

Thanks for reaching out to us. I'm afraid we don't know who manufactured your window, but the 15-177 pivot shoe looks like a match for your old one. The Series 152 coil springs are sold separately and are designed to screw to the side of the pivot shoe. You'll have to check if there's a stamped weight code on the tongue of the old coil spring.

Please let us know if you have any questions. 

No, you'll want to look on the coil spring's tongue for a stamped number, not the pivot shoe. If there isn't one, you will have to weigh the window sash on a scale and divide the weight by the total number of springs used in the window.