MiraCool Hard Hat Pads are a simple and effective way to beat the heat. Simply hydrate in cool water and attach to your hart hat to feel instant cooling relief. Avoid the effects of heat stress, and stay outdoors longer with this great cooling devise. Filled with special "MiraCool Crystals" Cooling Crystals can hold up to 1000 times their weight in water 100% Cotton Fabric for comfort Reusable Over & Over Works without freezing or ice Increases alertness and productivity About The Cooling Hard Hat Pad: Fastens easily with Hook & loop Air movement around suspension assists in the cooling effect Activates in Minutes Cooling lasts for hours Comfortable Fit Helps prevent heat stress Miracool Cooling Hard Hat Pad