This helmet is made of ABS hard shell and shock-absorption EPS foam for impact resistance. It features 11 air vents, adjustable dial and side straps, and comfortable inner pad to bring you wonderful sports experience. It is great for cycling, skateboarding, skating, scooter, and other sports.<br/>Features: Injection ABS shell and EPS foam for impact resistance and light weight. 11 air vents to reduce sweating and stay cool. Adjustable dial for a customized fit. Small: 52 - 54cm / Medium: 55 - 57cm / Large: 58 - 61cm. Adjustable side straps and quick-release buckle. Moisture-wicking soft inner pad, removable and washable. Great for cycling, skateboarding, roller skating, scooter, and other sports.<br/>Specifications: Material: ABS &#43; EPS Color: Black / Blue / Pink / Red / White / Yellow (optional) Size: S / M / L (optional) Head Circumference: S: 52 - 54cm / 20.5 - 21.2in M: 55 - 57cm / 21.6 - 22.4in L: 58 - 61cm / 22.8 - 24.0in<br/>Package List: 1 * Sports Helmet Injection ABS shell and EPS foam for impact resistance and light weight. 11 air vents to reduce sweating and stay cool. Adjustable dial for a customized fit. Small: 52 - 54cm / Medium: 55 - 57cm / Large: 58 - 61cm. Adjustable side straps and quick-release buckle. Moisture-wicking soft inner pad, removable and washable.