Evaporative Cooling 6-Panel Sports Hat Baseball Cap, Khahi, One Size, #6594 HyperKewl material is integrated directly into hat panels. Provide 5-10 hours of cooling relief per soaking lightweight and durable, includes mesh vents for air circulation 6 panel hat designed specifically for people working outdoors Mesh polyester outer, w/HyperKewlTM fabric inner and water repellent taslan inner