Mini Hornit helmets (or LIDs as they like to be known) are a LOT, cooler than other kidsÃ¢â‚¬â„¢ bike helmets. Designed with the spirit of individuality, there is a helmet to suit any personality. But, most importantly they keep heads safe. Fully adjustable, comfortable, lightweight, they also come with the added safety feature of an integrated LED light. Available in sizes S and M, which are ranged to fit all children; Small: 48-53cm, Medium: 53-58cm. The integrated LED light features 3 modes, with battery power lasting 10 hours constant, 20 hours flashing, powered by 2x AG3 cell batteries.