Was pretty skeptical about these, but had tried every other kind of bra on the market and still hadnt found one I liked with my backless tops/dresses.  So I gave these a go.  They are comfortable and stayed put all day, even in 88 degree heat and humidity!  Looked invisible under my crepe tank top.  I don't know that Id wear them with a really fitted/tight tank, but with a looser tank they were great!  They didn't lift my C cups to the heights of a pushup bra, but they definitely gave them decent lift and shape while blocking headlights from showing through my thin shirt.  And Im a 43 year old gal...so while my goods aren't down around my waist yet, they also aren't where they used to be when I was 20.  These shapers are definitely a keeper and really surprised me with how well they worked.  Took me two tries to get them on smoothly, but by the second time it was perfect.  I think if you were any larger than D cup you wouldnt want these.  But if you need a backless bra, this may fit the bill.