The Sun Tripper Cap offers effective sun protection performance in stylish urban fashion. This cap is for the young - and the young-at-heart. Lightweight, breathable sun protection with firm folding brim - fits in most pant or jacket pockets! Slipstream mesh vent panels, and moisture wicking sweatband keeps you cool in the sun. Detailed with external adjustable sizing cord and internal crown pocket for carrying cash or credit card. UPF 50+. Lightweight 2.6 oz. Sizing (Head Circumference): Medium: 21-23", Large: 23-25".