I bought some Cavallo boots for my newly barefoot gelding. I read the threads and bought the Sport version since that shape suited his hoof better.
My farrier had just pulled the gelding's shoes and we measured with both the Cavallo size guide and a regular tape measure.
The gelding's hoof was right at the line between size 2 and 3.
So I bought size 2 because I figured size 3 would be boats on him.
Got the boots today and tried them on him.
I can get them on but it's not as easy as it looks on the Cavallo video, where they just slip right on.
I have to pull pretty hard to get them on. Once on, the little button hooks fit on the tightest hook or else they seem loose.