I don't know how to do online chat & I was unable to reach (888) 991-1929, so I took attached photo
which coil should I buy?
Attached are photos of the front and back of the pivot shoe. Width one and quarter inches, thickness is 9/16 inches
We just need 4 to 6 coils, half inch wide, about 50 inches long
The number on the coil is 9 or 6, my double hang window weights 18 pounds
Thank you!