I went to Michaels on the off chance that they had an "O" and they did not, of course. But I was looking at the Boye size P hook, and it looked small to me. So I brought it home to compare with my Lion P, and it IS smaller.
Lion Brand P is 11.50 mm. It won't even fit in my needle sizer thingie.
Boye P is 10.0 mm
So I got the Boye and maybe it will work as an "O."
THEN--I was looking at the Boye N hook I used to start the baby blanket, and I inserted it into the N slot in the Susan Bates needle sizer, and it was so big. It actually fit in the "L" slot. I'm just amazed at what I'm seeing here. Why does an N hook fit in the L slot of the sizer???
Sorry if I have bored and confused anyone...or maybe I'm just confused.