As they practice their BMX skills or cruise around the neighborhood, they will feel safe and confident wearing the Bell(R) Youth Block Bike Helmet. The strong ABS hard plastic shell and EPS liner offer a comfortable and tight fit while 10 vents provide airflow and breathability to help keep them cool. The Block Helmet is designed with a lower profile with a more curved shape on the sides and back for maximum protection. FEATURES: Street skating and BMX bike helmet Classic skate style design Features a lower profile with curved sides and back for added coverage Ventilation: 10 vents Durable ABS hard plastic shell with EPS liner Bike and skate certified: CPSC Bicycle, CE EN1078, ASTM F1492-08 Skate Complies with U.S. CPSC Safety Standard for Bicycle Helmets for persons age 5 and older SIZING: XS: 49-53 cm S: 51-55 cm