FEATURES: Compact design 18 wind tunnel vents with internal channeling keeps things cool even when the riding gets rowdy Quick dry padding Slimline webbing Reflective accents In-mold construction fuses the polycarbonate outer shell with the EPS foam liner Complies with U.S. CPSC Safety Standard for Bicycle Helmets 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 Roc Loc(R) Sport MIPS fit system offers a stable and custom fit SPECS: Universal Fit Adult Size: 21.2 in. - 24 in. / 54 cm - 61 cm