Outer material is lightweight and durable polyester. Upper crown woven section allows for fast evaporation of sweat and improved airflow. Fast drying as it does not soak up moisture. Highly stain-resistant fibers, making it easy to keep clean. Minimal overlocked flat seams enable improved stretch and comfort. Contoured shape to fit neatly under helmet. Stretch grip-strip around forehead and ears for an improved fit with stretch elastic binding. Machine washable at 104 degrees. One size fits most.