There is the standard size and the mini. I would have said I don't have such a small head. If I now do the measurement to determine whether standard or mini according to the Shokz instructions (behind ear to the other behind ear > 23.5 cm = standard), however, I pretty clearly have to take the mini. Now I'm confused, because 1: Obviously many more standard than mini are sold 2: I would clearly need a mini, even though the head is not that small. How do you see it, what is your experience with the size?