polyester Cup, Fiberfill: 100% Polyester. Cup lining: 100% Nylon. Center, Back: 86% Nylon, 14% Lycra spandex. Exclusive of other trim and elastic. Lightly lined seamless cups offer sleek support and smooth shaping. Stretch sides and back for a more comfortable fit. Adjustable stretch straps on A, B & C cups. Adjustable non-stretch straps on D cups Machine wash warm water with like colors.