Specifications: Material: PC Shell + EPS Buffer + Polyester Lining Technology: Integrated Molding Head Size FIt: 58-62cm(22.83-24.40in) Outside Size: 34*22*19cm(13.38*8.66*7.48in) Internal Size: 17*22cm (6.69*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