Champion Gun Sight Question

[Gik-tal]

I'm looking to buy a new fiber optic front sight for a 1911, problem is I cannot find measurement information on the sights. I emailed midway a few days ago with this question but have not heard back form them on it. Hoping someone else has a set and know how the measure them properly. From what I can tell they are measured from the top of the dovetail mount but on the fiber optic sights are they measured to the center of the fiber optic rod or to the top of the sight like regular sights are.