I have bought these over and over again.  They are my post shower slippers.  Rub on lotion and I stick my feet in these while I go about my routine.  I am a 9.5 shoe size and did by the x large last time but they were a little big so I went with the 8-9 size this time and they fit and stay on.  I toss them in the washer just about every week so eventually they do start to wear out but then I just purchase the next ones!