My C-cup breasts bunched up near neck opening like in a huge singe cup push up bra. Looks hideous. I guess this binder would do OK for cup size A, but don't bother if your chest circumference is big or cup size is B and above. The only thing that works, in my opinion, is medical cotton elastic compression bandage 6" wide210", like Avcor Honeycomb/X-Ten Latex-Free Elastic Compression Bandages, put over a sports bra.