Whenever there is a significant rain storm, the area in front of my apartment floods.  A few week ago, I found myself stranded when heading out for work. I immediately purchased these to slide over my dress shows. I wear a 10 M dress shoe and the fit was just right although the size says it's for 11-12.5. So they seem to run small. If my shoe size was a 10.5, I don't think it would have fit.