Tilley has combined the classic five-panel silhouette with their signature Airflo technology. The two bonded mesh panels along the top provide exceptional ventilation while the nylon construction provides water repellent and UPF 50+ rated sun protection. This clever technology helps make biking, running and everyday adventures that much cooler. Rated UPF50+ PFC Free DWR Finish Elastic Sweatband Bluesign Bonded Mesh for Ventilation Breathable Material