Bought to replace a product called 'No Peek' that I can't find anymore.  These are similar a bit thicker and more rigid.  This is not to say they are too rigid, just moreso than the others.  The sizing information was confusing.  So I took a guess.  They are a little too small, but are adequate at concealing.  They tend to shift position during the day.  I have to pay attention or they start to work their way out of my bra.  I might sew them in.