I am 5'6" tall and weigh 138lbs. and purchased the size small. I have a very small chest - 34AA or 34A cup. So I am usually looking for lingerie without cups or actual bras, as I inevitable cannot fill them out. This does not have a bra - so no cups, underwire or support. For a smaller sized breast, this top is amazing. I love how it looks - it is pretty see-through and nipples are not hidden, but it has a nice plunge so it gives the illusion of cleavage. If you have a very large bosom, I am not sure this piece will support you well, and you might fall out of it, but for smaller gals - yes, it totally works!