No markings

Hello, thank you for posting,

Please review the style of the 15-180 pivot shoe that is compatible with the Series 190 coil springs. Compare the dimensions below to confirm a good fit! 

Alternate image for 15-180

There should be a number stamped on the original coil that indicates the weighted option needed. If there are no markings, please provide the weight of the window sash to move forward. Also see the 15-182 bushing and 15-186 balance clip.

Let us know if you have any additional questions!