I tried it on and it feels pretty tight. It has something along the inside edge to help keep it up and also comes with straps which i really like incase i wanted to use it later for something other than my wedding dress.
I'm not sure if it'll stay up well over time. I'll have to edit later.
I'm usually a 34B so thats what I bought. It fits pretty well. Strap going around is just tight enough but the cup size could maybe be a little smaller for me. Overall very nice for the price.