SPEEDO Endurance Turbo Stroke Flyback Adult Endurance Fabric Best-selling, longest lasting training fabric. Endurance fabric: 50% Polyester/50% PBT. Front lined: For comfortable coverage and durability. 100% chlorine-resistant: Lasts longer than conventional swimwear. Maintains body-hugging shape: For supportive comfort. Resists sagging and bagging: Enhances durability. Premium color retention: Fade-resistant. Features One piece youth swimsuit. Flyback: Cutout, circle back: For flexibility. Thin straps: For better tan lines and comfort. 4-way stretch: For flexible comfort. Reinforced seams: For resilient, long-lasting wear.