Having only worn Dudes for the last 10 years, I am very disappointed with my most recent pair , Wally slip on recycled ( supposedly )leather. First they make my feet sweat badly and feel very drawn . On examining them very closely, they are PU , definitely NOT real leather. I have 4 other pairs of older leather Dudes, none of which give me this problem and are obviously and without doubt real leather. I don’t know if this is because they’ve been taken over by Crocs or not but I’ve never had a problem with Dudes before and never had man made material described as leather before.