Micro's quality branded helmets are specially designed for scooting. Bike helmets often do not have the protection for the back of the head that our Micro scooter helmets have due to the need to angle the head back when riding a bike. Comfort and Function: These durable helmets feature an injection-molded ABS shell over a shock-absorbing liner for high-impact protection. A spin dial and adjustable straps ensure a perfect fit,while multiple air vents help you keep your head cool. Extra padding for comfort and safet Measuring & Sizing: We believe that every child should wear a properly fitted helmet when scooting which is why we have created a range of eye catching designs in two different sizes for safety and style. Please measure your childÂ's head to ensure you order the correct size. For 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. All Micro helmets are certified for scooting, cycling and skating (EN1078 Safety Standard) and have Watch our video for instructions on how to meaure. Sizes: Small: 44 - 48.5cm Medium: 44 -48.5cm Large: 48.5 - 53cm X-Large: 48.5 -53cm