Their most popular Training hat, the Outdoor Research Swift Cap has sun protection and a full mesh liner crown for superior ventilation in warm weather, while the shaped brim and nylon panels offer serious protection from the sun. Fabric Performance: Water-Resistant Breathable Lightweight Wicking Quick-Drying TransAction Headband Mesh-Lined Crown UPF 50+ Design Features: Dark Fabric Under Brim External Breathable Mesh Panels Embroidered OR Logo Functional Details: Quick Release Buckle Back Packable Weight: 2.5oz One Size Fabric: Main Shell: 100% Supplex nylon plain weave Mesh lining & Side panels: 100% nylon