I really really like these and will order a few more pair of them, they fit me really well (im 5'3" and 112, wear a size 3ish sometimes 0/1 or even sometimes a 5, depending  on the style and brand) and they look great on me!
the material on the ones I ordered, which was the black ones is like a pleather material, and it is stretchy, so it can fit more than just a smaller size, but I don't think that this would fit a person that is large, id say through a big medium... and I recommend these to everyone in that size range, that wants a nicely made, good material, pair of sexy undies!!! these are made very well, a great price also, and came a lot faster than what I thought they would, I was surprised to get them so soon! great purchase!