Features: Shell: Impact Resistant, Scratch Resistant, Corrosion Resistant, Heat Resistant, Moisture Resistant, Dimensionally Stable. Buffer Layer: High Elasticity, Good Cushioning Performance. Lining: Breathable, Comfortable Skin, Sweat and Deodorant. Quick Buckle: Adjustable and Convenient. Specification： Type: Half / Open Face Color: Matt Black Materials: ABS (Shell) + EPS (Buffer Layer) + Fiber Fabric + Sponge (Lining) Unisex Size: Small size is <56cm, Medium size is 56-58cm, Large size is 58-60cm Weight: 300g Package List: Helmet x 1 Piece Note: Not suitable for motor vehicle use To measure your head size, measure the circumference just above the ears and across the forehead approximately 1" above your eyebrows. If near the top end of a size band we suggest you go for the next size up.