Ergodyne Chill-Its 6715CT Evaporative Cooling Interior Hard Hat Pad, Blue LONG LASTING INSTANT COOLING RELIEF Can last for up to 4 hours on a single soak. Simply re-wet to increase cooling duration EASY TO USE AND ACTIVATE Run under water for about a minute, twirl in the air, and it's cool! Secure in your hard hat or helmet by attaching to suspension for drip-free cooling relief as temperatures rise. 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! MACHINE WASHABLE Wash in cold water with mild detergent and air dry