This bra-liner solves the problem of peek-a-boo and sweat during the seasons when you wear light clothing. Its special design prevents peek-a-boo shoulder straps and cleavage, and the double layer of moisture-wicking, quick-drying fabric provides wide coverage around the armpits and back, where sweat tends to build up. It's not see-through, and even if it does peek out, the color doesn't look like underwear.