Sturdiness - incredibly sturdy. There is one issue which is why I gave it four stars. About 5 dollars without shipping (shipping was about 4 or $5) so I shouldve known what I was going for, but I didnt think theyd be this cheap. I read the reviews about them being too small and was a little nervous because I have a wider foot but these are comfortable. She wore size 6 Nike so. So, I pulled the trigger. The charging cable is fine, fits but my Beats true wireless still doesnt charge. I wore these on a vacation in Europe recently and did a ton of walking up hills on cobblestone streets and so it wouldve been nice for it to feel more firmly attached to my foot, but otherwise they were very comfortable from day one. Eine bequeme Sandale, in der man auch mal eine längere Strecke zurücklegen kann. ally takes 6 months to a year of regular (almost daily) wear for that to happen.