I am actually going to buy another set of these. I absolutely love them! But I want to be even bigger. They will increase your bust size by at least more than 2 sizes. I have little ones so I do bend over alot to pick them up and I'm suprised that the inserts stay in pretty well, they do not move around much. Not sure what I would do with a swimsuit but in the meantime these are fabulous. They look totally natural, my husband didn't even know I had them in and asked what was up :) I even wear them with my sports bra in and they work fabulously. I'm getting another set because I'd like to see how Id feel bigger before I actually get a real lift and augmentation, currently I have pretty much zero breast tissue. Since I can truthfully answer NO when people ask if I've had breast implants when I do get my real implants in a few months no on will say anything, I'm hoping. Love these though and they will do in the meantime!!!