The inner hole fits over a 7.6 mm diameter crank with a flat edge that is cut off at 5.6mm and is 12.5mm tall. Not sure how else to describe it.

The outer hole fits over the base & spring of the can opener, which is 15.25mm diameter, 15.3mm deep.

The handle is a bit oversized so it's a bit easier to open the large 128oz cans I have.

I printed in ABS with 3 perimeters, so far very strong and easy to turn.