Help installing water softener yoke missing
 

I brought a hydro-quad water softener from someone. As the plumber says
it is fine just that it is missing yoke. I called Hydro quad for the
part but they are looking for serial number. All I have is a model
number so they are not ready to help.
One of my friend told me that I have to have yoke from hydro-quad
company only.
Is that so? Can't I order 3/4" or 1" nylon yoke from some other company
and use if with this one?

Please guide me.