FEATURES: Designed for road biking Float Fit(TM) system is lightweight and has a rubber over molded dial that allows easy adjustments 18 wind tunnel vents with internal channeling keeps things cool even when the riding gets rowdy Lightweight internal polycarbonate roll cage reinforces the structure Lightweight straps for comfort No-Twist Tri-Glides(TM) has quick-adjust fasteners that help keep straps flat and in place Sweat Guide(TM) pad pulls moisture away from the brow pad and eyewear Reflective decals for increased visibility Certifications: CPSC Bicycle, CE EN1078 Complies with U.S. CPSC Safety Standard for Bicycle Helmets for persons age 5 and older TECHNOLOGY Fusion in-mold polycarbonate shell with EPS foam liner provides strength and greater durability Overbrow Ventilation(TM) pulls in cool air through the air-channel matrix for full-head ventilation 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 SPECS: Circumference: S: 20.1 in. - 21.7 in. / 51 cm - 55 cm M: 21.7 in. - 23.2 in. / 55 cm - 59 cm L: 23.25 in. - 24.75 in. / 59 cm - 63 cm