I used them on one short run. I ordered them through Amazon so I can't return them. They are a men's size 9.5 / 42.5 but they feel at least a quarter size maybe half size smaller than that. If you've had any kind of La Sportiva shoes before then you know they size everything a little small.
They're a fantastic shoe though. They have a semi-minimalist feel and an inner liner that is comfortable and glove-like. They breathe well too.