Iconic Speedo Style. Paying homage to our legacy graphics, this sporty navy Muscleback swimsuit features a curved splice of our evolutionary HyperBoom graphic in contrasting shades of pink. Ideal for longer swim sessions, the muscleback style enables your child to achieve a full range of motion during their swim. A great choice for frequent training sessions, our EnduraFlex fabric offers higher chlorine resistance than standard swimwear fabrics and fits like new for longer with CREORA® HighClo™. In addition, nylon yarns in the EnduraFlex fabric are made from 100% pre-consumer waste, such as waste fabric from factories.