The product description says this suit is fully lined, but it is not. It is lined in the front beneath the ruched material. Across the back, there is only one layer of material. The fabric on the unlined suit was too thin, and ran a bit small.  The bust has built in cups, but there is no shelf bra. There is some elastic beneath the cups but its sewn directly to the front of the suit. There isn't much structure at the bust to keep the girls in place.