92% Meryl® Nylon, 8%Lycra® Spandex Meryl® Skinlife and DanceFresh® antimicrobial protection Provides support and modesty under dancewear and costuming TPU clear back strap has 2 hook positions on each end for adjustment Sizes XS and S provide support from "A" to "B" cups, and M, L, and XL provides support for "B" to "C" cup customers TPU clear shoulder straps adjust in length and strap position