The performance Columbia Sportswear Coolhead Cachalot Hat is the ultimate in cooling and protection, with all over Omni Freeze ZERO technology, which reacts with sweat to lower the temperature of the material. Add ventilation on the crown and UPF 50 sun protection on the front, top, and back flap, and youre ready for long days in the hot sun. Fabric is 86% polyester, 14% elastane ZERO Flex Stretch woven. Omni Freeze ZERO sweat activated, super cooling technology. Omni Shade UPF 50 sun protection. Adjustable drawcord and toggle at back for a secure fit. Vented crown. One size fits most.