Specifications: Material: PC Shell and EPS Buffer and Polyester Lining Technology: Integrated Molding Head Size FIt: 58-62cm(22.83-24.40in) Outside Size: 34 x 22 x 19cm(13.38 x 8.66 x 7.48in) Internal Size: 17 x 22cm (6.69 x 8.66in) Weight: 385g(0.88lb) Vent: 17 SAFETY FIRST: Combined with impact-resistant materials and mature helmet design solutions, a solid structure is made to maximize head safety, and provide sufficient cycling protection SOLID CONSTRUCTION: Full Coverage Tough polycarbonate outer shell fused helmet's impact-absorbing EPS foam liner for durability without excess weight, riding with ultimate free and comfortable READ TO GO: Sleek design and dazzling colors, it's combined with 17 wind tunnel vents and internal channeling for heat dissipation during long journey riding ACCESSORIES: With washable and removable padding inside, a big visor for sunlight proof and protects the head from small objects SIZE ADJUSTMENT: The rear dial for customized circumference with the easily adjustable system, fits most youth, adults, men, and women's head sizes