?Impact Resistant?: Certified by CPSC, with PC external shell and EPS high density foam for durability and resistance. ?Ventilation?: Up to 19 venting holes allow hot sweat to escape in time, bid farewell to sultry and humid, streamlined design can effectively reduce wind resistance during riding. ?Lightweight?: Only about 4 eggs weight, wearing friendly & reduces weights on your neck. Even if children ride for a long time, they would't feel the presence of a helmet. ?Sizing for Kids?: Point 1- Find the fullest part of the head, about 1 inch above your eyebrows and ears, use a soft measuring tape. Point 2- Please measure your head in centimeters to get a accurate measuring. Size S(49-52CM) is the minimum size of the helmet, size M(52-55CM) is the largest size, if you have problem with choosing size, please feel free to contact us. ?High Quality Design?: High range paint with a very modern matte finish. The Detachable visor can be removed in seconds, allowing you free to choose between roads-style and mountains-style.Rotatable and adjustable dial (3D) fits every head comfortably and doesn’t feel loose.