About this item SAFETY - This GROTTICO bike helmet meets US & EU cycling standards. ADJUSTABLE DIAL & STRAPS - The adjustable fit system for men and women. 2 sizes for choice, suggested head circumference: M (55-58CM), L (59-61CM) INTEGRATED SAFETY REAR LIGHT - Bicycle helmet with USB rechargeable light. Best for night riding with 3 lighting modes, Steady, Flash and Wave. TOUGH & LIGHTWEIGHT - In-mold construction fuses a tough polycarbonate outer shell with the impact-absorbing foam liner. The fusion process makes in-mold helmets lighter and cooler than traditional helmets. KEEP YOUR HEAD COOL - 23 vents keep ample ventilation. Provide one more set of helmet replacement inner pads and two different color visors to collocation.