57
I use these alteast 3 times a week while mountain biking. Fits my foot like a glove and still holds water. Hands down the best shoes I've ever had.
One thing to note though is that these are not for winter use. The rubber gets hard in cold weather and has zero grip on ice and I truly mean zero. Ask me how I know lol
They are usable, but the grip is really terrible. My old airpower pro I think was advertised as having "improved grip on snow and ice" or something like that. I wonder what they started with if that was the improved sole.
I still use them on really wet days and places after closer to ten years.
Edit: actually they must be over 15, but under 20 by now.