Description of Outdoor Research Swift Cap This hat has a full mesh lining for increased ventilation in warm weather. The shaped bill and nylon panels offer protection from the sun. Features: Quick-dry, nylon Supplex® fabric front and top panels Mesh liner crown aids ventilation Shaped, plastic-stiffened bill TransAction™ headband for comfort and moisture management Quick-release buckle adjustment Avg. weight: 2.5 oz./71 g (One Size)