The Giro Adult Artex MIPS Bike Helmet provides a cool, breathable fit with its 25 vents and Roc Loc(R) 5 Air MIPS fit system. Equipped with Multi-Directional Impact Protection System, the Artex helmet protects from rotational forces during an angled impact. It has a removable visor and deeper coverage. FEATURES: Multi-Directional Impact Protection System (MIPS) reduces rotational forces from certain impacts for more protection Four-piece polycarbonate interlocking hardbody shell with full hardbody wrap Roc Loc(R) 5 Air MIPS fit system allows airflow and a custom fit with added protection in case of impact Ventilation: 25 vents with internal channeling Internal channeling forces air to flow over the scalp for cooling power In-mold construction fuses the polycarbonate outer shell with the EPS foam liner Removable visor Complies with U.S. CPSC Safety Standard for Bicycle Helmets for persons age 5 and older SIZING: S: 20"-21.65"/51-55cm M: 21.65"-23.25"/55-59cm L: 23.25"-24.8"/59-63cm