Ergodyne Chill-Its 8935CT Evaporative Cooling Ranger Hat Hi Vis Lime, Small/Medium LONG LASTING INSTANT COOLING RELIEF Can last for up to 4 hours on a single soak. Simply re-wet to increase cooling duration. Vented mesh side panels for increased air flow and breathability EASY TO USE AND ACTIVATE Run under water for about a minute, twirl in the air, and it's cool! Wear for drip-free cooling relief as temperatures rise. WIDE BRIM Protects and blocks face from the sun DURABLE AND REUSABLE Product can be re-used over and over again. Let air dry (material will get stiff), re-wet until soft and it's ready to use! HIGH VISIBILITY Made with ANSI certified polyester and reflective tape for increased visibility protection Size: S/M (21-22.5") L/XL (22.5-24")