Double hung window

Hello, thank you for posting, 

Please review the style and dimensions of the 15-087 pivot shoe. Compare to your original to confirm a good fit! This shoe is compatible with the Series 180 coil springs. 

There should be a number on the spring that indicates the weighted option needed. If there are no markings, please provide the weight of the window sash to move forward. Thank you! 

Detail of 15-087

Hello,

For an 18 pound window sash, you can use (1) S180-09 coil spring on each side of the window sash. These springs install into the 15-087 pivot shoe. These parts are interchangeable for both sides. Let us know if you have any additional questions!