Reporting question for Knob - Black, Line, Set Screw, 1.0" diameter x .6" tall

Product:
Knob - Black, Line, Set Screw, 1.0" diameter x .6" tall

Question:
What is the diameter of the recess on the back side of the knob. It's there to fit over the nut that holds the potentiometer.

Answer:
The diameter measures .68".