FEATURES: Tough 4-piece polycarbonate construction Wind tunnel vents with internal channeling keeps things cool even when the riding gets rowdy Quick dry padding Slimline webbing Complies with the US CPSC Safety Standard for Bicycle Helmet for Persons Age 5 and Older TECHNOLOGY: Equipped with MIPS(R), the Multi-Directional Impact Protection System, so you not only stay cool but stay safe with extra protection and durability Integrated MIPS(R) reduces rotational forces while enhancing comfort and fit Hardbody outer shell extends within the helmet and fuses with the EPS foam liner using Giro(R)'s In-Mold process to increase durability and safety without any added weight Roc Loc(R) 5 MIPS system fuses the trusted protection of MIPS systems with customizable positioning options and increased protection SPECS: Circumference: S: 20 in. - 21.75 in. / 51 cm - 55 cm M: 21.75 in. - 23.25 in. / 55 cm - 59 cm L: 23.25 in. - 24.75 in. / 59 cm - 63 cm