The Chill-Its 6634 Cooling Headband is a low-profile wrap that wicks away sweat and moisture when worn dry and provides evaporative cooling relief when worn wet. The stretchy performance knit fabric and contoured design makes for a snug, comfortable fit on most head sizes. This skull wrap is rated to UPF 50+ for protection against the sun's harmful UV rays and features an anti-odor treatment for fresh all-day wear. A reflective accent enhances visibility in low-light conditions. The low-profile design fits comfortably under a hard hat or helmet and is a great option for those with longer hair\/ponytails. Ideal for construction, landscaping, roofing or anyone working in the heat. It can also be used to reduce the risk of heat stress for outdoor recreational activities. In order to activate, just soak in water until saturated, then wring out excess water. The evaporative cooling process begins instantly and lasts for hours when worn in environments with suitable airflow.