This swimsuit features a wide strap, adjustable butterfly strap back design, for increased suit coverage and support. Offering long lasting durability and maximized resistance to chlorine. 52% Polyester /48% Polyester P.B.T. The top runs a bit larger than the bottom. This is recommended for those with a larger chest size. If you receive this product and the top or bottom doesn't fit, you can exchange for a larger or smaller size.