Details- lightweight, bluesign, recycled FLEXweave woven fabric.fast-drying, anti odour, performance-ready COOLmatic|PLUS MIKRAmesh™ fabric on top, sides and headband.pliable SOFTflat brim for easy packability.reflective detailing for night run visibility including branded webbing.S/M 56.5 cm +-. M/L 58 cm +-. L/XL 60 cm +-.machine washableciele athletics™ million miles guarantee.designed for people who run. main fabric: 100% recycled polyester.mesh fabric: 100% recycled polyester care- wash cold water- hang to dry- no tumble dry- do not use softner- wash with like colors- do not bleach