The T5MO Tilley Hat, designed with a medium brim, is made of a soft, sueded certified organic cotton with ?" polyester mesh. The mesh helps to both ventilate warm air out and allow cooler air to flow in while the sturdy cotton fabric is rugged yet exceptionally lightweight. Features: Guaranteed for life not to wear out Insured against loss Excellent sun protection, rated UPF 50+ Dark underbrim for glare protection Repels rain, floats Ties on in the wind Machine washable, won't shrink Secret pocket Medium brim with ?" ventilation mesh