Remi was designed with the everyday rider in mind. Ventilated and breathable. Removable/washable interior. Built-in visor. Stylish AND safe. You're ready to roll. Features: Bike and skate helmet designed for everyday use 11 rectangular air vents for optimal airflow Interior padding wicks away sweat and is removable for easy cleaning Easy-to-adjust nylon straps and an ErgoKnob dial for a snug fit Complies with the U.S. CPSC Safety Standard for Bicycle Helmets for Persons older than Age 12 Sizing: Small Head Circumference: 21.25 in. - 22.5 in. / 54 cm - 57 cm Medium Head Circumference: 22.5 in. - 23.25 in. / 57 cm - 59 cm Large Head Circumference: 23.25 in. - 24.5 in. / 59 cm - 62 cm