The latest Micro helmets have an integrated LED light and are designed for a firm ergonomic fit for the ultimate in safety. Lightweight with inbuilt ventilation the protective helmet is made for comfort on both long and short adventures. Parents can have peace of mind about their kids scooting both near and far. - Adjustable Chin Strap - Interior padding for comfort - Integrated LED lightFor sizing, measure the circumference of the head from the forehead where the helmet will sit, across the furthest point on the back of the head. PLEASE DO NOT GUESS [S] Small: 48-53cm [M] Medium: 52-56cmOutside: In Moulded 100% PC shellInside: 100% EPS lightweight high-performance foam for maximum preventionInner Fabric: Polyester Fleece on PE Foam Pads