Fits children approximately ages 3 to 5 years. Fits heads: 48cm to 52cm (18.9 In. to 20.5 In.). Well ventilated for extra comfort. Features True Fit, 1-step adjustment for a perfect fit every time and Pinch Guard buckle for no-pinch buckling. Extended rear helmet coverage for added protection. High-impact plastic outer shell for added durability and protection. Certification Complies with the US CPSC Safety Standard For Bicycle Helmets For Persons Age 1 and Older ( Extended Head Protection) Helmet design may vary.