Made of 100% polyester this lightweight and elastic cap wicks away sweat keeping you dry and comfortable. Its elastic design fits most head sizes stretching to accommodate various head shapes. With a breathable honeycomb mesh design this cooling skull cap keeps you cool while the high-stretch nylon polyester provides a snug fit that won t feel too tight. It s thin and lightweight making it perfect for wearing under a cycling or motorcycle helmet or a hard hat. Whether you re hiking running working out cycling riding a motorcycle or engaging in other physical activities this skull cap is suitable for all your needs. It effectively prevents moisture dirt and odor build-up in your helmet making it a must-have accessory for any activity.