Rear light for Safety; Equip with 3 modes Helmet Led Rear light for safety Ultra Lightweight for Comfortable; Only 0.49lb In-Mold polycarbonate shell with EPS liner,It very comfortable to wear Ample Ventilation; 24 Vents keep Ample Ventilation for ultimate temperature regulation and reducing resistance Adjustable dial to customize fit; Fits head sizes(M/L) 56-61cm(about 22-24inch) Helmet Rain Cover;Come with Visor and Rain Cover Protected from sun ,elements, wind, rain, dust and anti-aging