Versatile Design: 2 in1 Kids Helmet offers switchable full helme and half helmet, disassembly and assembly are very convenient, providing flexibility for different riding conditions. The extended brim design helps block the sun and protect the eyes. Lightweight and Comfortable: Cycling Helmet is made of lightweight EPS material to ensure comfortable and stress riding. Ventilation and Windproof: Bicycle Helmet has multiple ventilation holes, good breathability, low wind resistance, and ensures a smooth ride. Protection and Shock Absorption: Skateboard helmet uses EPS shock absorbing lining to provide head protection against impact and collision. It also has a removable lining pad and chin sponge pad, skin friendly , which is breathable, sweat absorbent, easy to remove and clean. Adjustable Circumference: Kids Bike Helmet's circumference can be adjusted to fit different head shapes (51cm-55cm/20.08inch-21.65inch). Specification: Material: PC EPS Size Chart: Head Circumferenc: 51cm-55cm/20.08inch-21.65inch Package Includes: 1 Kids BikeHelmet Note: Please allow slightly errors 1-2cm differences due to manual measurement.