Can anyone help me measure a shift knob adapter?
 

My friend gave me a shift knob and I know our shiftknob is m12x1.25.
The thread adapter's inner diameter is m10x1.25 I think. It's just a brass insert that goes inside the shift knob. I can't figure out the outer diameter.

Its 18.75mm tall and 17.75mm wide and has 12 threads.

Are you asking for the OD of the adapter or its thread pitch?

Both! Haha

If the inner diameter is 10x1.25, and the shift knob is 12x1.25, wouldn't the outer diameter also be 12x1.25? It can't be 8, since the ID Is already 10.

Wait no the inner diameter is m10x1.5 whoops typo.