I purchased these to give to my mother, who is taking water aerobics. She's not too steady on her feet, and I was worried about her slipping on wet surfaces. The size seems correct (I ordered a M to fit a women's 9.5 wide foot), although I found it difficult to squeeze the shoes on myself, and my feet are the same length as hers but much more slender. The plastic does not have any give to it, and I've seen the other review where someone mentioned the back strap broke quickly (probably from the stretching, trying to get the sandals on/off). They fit me nicely, once I got them on, and felt very cushiony, but I know my mom would not be able to get them on her wider feet. She also has some swelling around the top of her feet and ankles. The plastic fits very snugly in these areas, and it would not have been comfortable for her, so I had to return them. If they were a little looser around the ankle/back strap area, I think they would have been perfect.