These insert cutlets are NOT for swim suits, especially not bikinis. Unless your bikini has a place for inserts (and has its own nipple blockage cloth), this is NOT for bikinis. There are pushup inserts out there specifically triangular shaped for bikinis and whatnot, and THIS product is not it. If you're going to use this, use it with a full cover bra, kinda like the one in the image (white bra on box) or like.. with super cover bras that cover everything but the cleavage. Wearing this with demi cover bras will only lift your nipples out into the open if not worn properly. Also, make sure to buy fashion tape. These cutlets do move around, especially if you move around, raise your arms, bend over, etc. Also, these work better with wire bras because with regular bras, they bulge and create a sagging look for a profile view. These inserts give you about an additional cup of lift. I'm a B, and with these inserts, they are like a full throttle, voluptuous B.. when worn properly with the appropriate bra, of course.