Oops, I just saw that I didn't label the sizes.
Across the top are 5, 7, and 9.
The bottom row are 11, 13, and 15.
BTW, some Ropers, one used to be able to safely say all, use a half heel.
The measuring system for that type of heel is a whole 'nuther kettle of fish.
They run from 10-11, 11-12, 12-13, 13-14. I don't think I've ever even seen any larger than that.
Half heels are generally washerless, using an auto nailer, a coil nail machine.
Vibram is the only brand I care for with washer type half heels.
As to ordering half heels without a size reference, you might get lucky and get a salesman who will take the measurement of your heel base and help you with the correct size.
Welcome to confusion. If you're looking for logical standardized references, good luck.