One Piece Workout Romper Stretchy And Breathable Fabric: 90% Polyamide and 10% Elastane. The seamless bodycon workout romper is breathable and good at moisture absorbing and sweat releasing. High elastic with four-way stretch keeps freedom of movement, not too tight to cut into your body. Slim fitted, smooth, comfort, not see through. LTKActive LTKFitness LTKMidsize